Frequently Asked Questions
Shellfish Holding Systems
The main questions we get asked about our Shellfish Holding Systems.
Our cheapest lobster tank is £5,000 + VAT and delivery. This includes a filter and seawater chiller.
The Lobster Pod range starts at £12,000 + VAT and delivery for a 100Kg shellfish capacity system.
We also make a Crab Pod tank with integrated filter from £12,000 + VAT and delivery for a 100Kg capacity system. For larger quantities our 750Kg capacity Crab Pod at £25,000 + VAT and delivery is the best value.
We would recommend changing 20% of the seawater every 4-6 weeks.
Shellfish naturally produce ammonia. Ammonia is toxic to shellfish. The good bacteria on biological filters such as our moving bed biofilter consume the toxic ammonia and turn it firstly into nitrite then less harmful nitrate. The level of nitrate builds up over time. Eventually this will become harmful to shellfish. In the sea algae and seaweed consumes the nitrate however in a recirculation system the only way to reduce the nitrate is to do a water change.
If the water is dirty, smelly or the ammonia levels are high then change the water as soon as possible.
You may need to change the water more often or change a larger percentage if storing crab (especially velvet crabs).
During the initial maturation phase of the filter you will need to do larger water changes more often until the good bacteria have grown and multiplied to deal with the ammonia.
Associated questions:
Can I use natural seawater for my lobster tank?
Yes, we would recommend using raw seawater if you can as long as it is clean and free from pollutants.
If you can’t get seawater then tapwater with a salt mix is okay (see FAQ on using tapwater).
Can I use tap water for my shellfish tank?
Yes, you can use tap water with salt added for your shellfish system.
You should always mix your tap water and salt in a separate tank and allow it to sit for over 24 hours to ensure the chlorine in the tap water has gassed off and ensure the salt is well mixed. Follow the mixing instructions provided by the salt supplier.
Chlorine is harmful to shellfish. It bonds with the ammonia produced by the shellfish to create chloramines (see Chloramine question). Make sure any water you use is dechlorinated (and perhaps test for chloramines in your tap water first).
We recommend Peacock Salt which is made for shellfish and contains not just the right salt levels but essential minerals too. Tell Peacock Salt we recommended them when you order!
Although you can use tap water mixed with salt if you can get natural seawater we would use this. You will not have problems with chlorine and it can be put straight in the system saving on the cost and space of a mixing tank.
How do I collect seawater to use in my shellfish tank?
We collect seawater using a water tank on a trailer (towed by our trusty Landrover Defender) and a small generator and submersible pump.
First find access to a good, clean area of the sea which is safe. We collect seawater from further out the Firth of Forth at Burntisland as it has a good slipway which is open to the public and it has cleaner water than we have nearby in Dalgety Bay.
At high tide put the pump to the bottom of the water as far out as you can. Avoid any areas with contamination e.g. oil or paint or too much agricultural run-off. If the seawater is really mucky it’s best to avoid it. Although our filter will clean this water it will take time and this can delay putting in shellfish or affect the shellfish already in your system. If the sea is too far, too mucky where you are or you can’t get safe access then you can use tap water with a salt mix (see FAQ on using tap water).
How much water does a shellfish tank hold?
| System | Water volume | 20% = water change volume |
|---|---|---|
| 100Kg capacity Lobster Pod | ||
| 150Kg capacity Lobster Pod | ||
| 200Kg capacity Lobster Pod | ||
| 250Kg capacity Lobster Pod | ||
| 300Kg capacity Lobster Pod | ||
| 750Kg capacity Crab Pod | ||
| 250Kg capacity Shellfish Tanks |
Yes, unless you have access to fresh seawater 24 hours a day then you will need a filter on your shellfish tank and even if you change your seawater regularly a filter is a good idea to use your tank as a recirculation system whenever you can’t get water e.g. stormy weather, local pollution issues, vehicle breakdown.
We have designed a unique filter to deal with the shellfish waste and ensure you always have clean and clear water.
The filter has five stages:
The seawater flows through the Mechanical Filter (we use filter sponges and filter socks) to remove all particles and waste;
The water then flows through the Chemical Filter (activated carbon in a filter sock) which ensures the water stays clear;
Next the Biological Filter (Moving Bed Bio-filter with efficient plastic filter media and a filter block) grows good bacteria which consume the harmful ammonia the shellfish produce turning it into nitrite then less harmful nitrite;
The Protein Skimmer removes the oily waste to ensure optimum oxygen exchange;
The Ultraviolet Steriliser denatures harmful bacteria and viruses.
This is a low pressure system using natural forces such as gravity which is energy efficient.
Associated Questions
What is filter maturation?
Good bacteria consume the ammonia which is produced by shellfish and this is turned into nitrite then less harmful nitrate. The good bacteria grow on the media in the moving bed biofilter. The bacteria take time to grow and multiply. We call this growth period maturation. Once the bacteria have reached sufficient numbers to consume all of the ammonia produced by the shellfish within 24 hours we consider the system to be mature. Most of our customers achieve this within 6 weeks although the speed of maturation depends on how much shellfish you have in the system, the temperature of the seawater and how often you change the seawater.
The optimum temperature for holding lobster and crab is between 8 and 12 degrees centigrade (and we would recommend 10 degrees centigrade). Langoustine are best held at 8 degrees centigrade. If you are holding langoustine and lobster or crab together (which is possible in our Lobster Pod system) then hold them at 8 degrees centigrade.
Our team includes Keith who has a PhD in Marine Biology and Laura who has a Masters Degree in Freshwater and Marine Biology. They have done a lot of research to find the optimum temperature for shellfish. We operated systems at 4, 8, 12 and 16 degrees to see what effect this had on the shellfish.
Although some fishermen and vivier operators believe that 4 or 5 degrees is the ideal temperature we discovered that at this low temperature the animals’ metabolism is too slow and they can’t purge themselves of any waste and recover from capture stress. They do not re-immerse in water as well once held at this temperature and the quality is reduced.
At 16 degrees centigrade the animals became very active and hungry and this weaker animals were more likely to be damaged.
Shellfish held at 8 and 12 degrees performed best. The metabolism was lowered enough to make them calm but they still purged any waste and recovered from capture stress. These animals survived for up to 6 months without losing any weight or condition (after 6 months they needed to be fed – please contact us for more information).
At each temperature we also did research on whether to feed the shellfish. The animals which were not fed performed better at every temperature for up to 6 months. The feed polluted the system and caused more problems with bacterial booms in the water, more cleaning and filter maintenance and more predation and damage to the animals.
Associated Questions
Do I need a seawater chiller on my lobster tank?
Yes, temperature control is very important and we recommend 8-12 degrees centigrade for lobster and crab and 8 degrees for langoustine.
Lobsters and crab should be stored between 8 – 12 degrees centigrade and langoustine at 8 degrees centigrade. Unless you have a cold room which operates at this temperature then a seawater chiller is the most cost effective way of ensuring this optimum temperature is achieved.
If your shellfish get too warm they will get weak and you will lose some. This can result in problems with water quality such as bacterial blooms and this in turn will harm your shellfish.
Our larger seawater chillers are also heaters and this can be important to ensure a minimum temperature throughout the UK winter months.
Seawater chillers can be expensive to operate – please see FAQ on how to keep your operating costs low.
Is it cheaper to chill the air or the water?
It is usually cheaper to chill the water than the air.
If you have a purpose built cold store which is well insulated with a self-closing door then chilling the whole room usually costs more.
The seawater chillers we use are very efficient. You set the thermostat to your desired temperature (we recommend 8 – 12 degrees centigrade) and if the water temperature is a degree above or below then the chiller starts working.
How can I keep the operating cost of my chillers low?
The day-to-day electric consumption of our insulated shellfish systems is very low however the seawater chiller can be expensive if it has to run all the time.
We would recommend making sure the room you put your lobster tank in should be as well insulated as possible.
Cover any windows or glazed doors to avoid heat gain.
Keep doors and windows closed and perhaps add a self-closing hinge to doors.
Make sure any heaters are turned off.
Don’t operate any equipment which generate heat in the same space.
If the heat builds up in the room put in good ventilation such as an Expelair fan.
Ideally put the seawater chillers outside as they will produce heat when operational. If they are outside build a cover with a roof to keep them out of the worst of the weather. If you can’t put the chillers outside then in another room or roof space is okay. The hose for the chillers is 2.5m long but if you need a longer hose to your chillers location then please let us know.
We offer doors, tank lids and filter covers as an optional extra which can help keep reduce heat gain.
All of our systems use single phase electric supply.
UK is 240v 50Hz (we can manufacture systems for North America and the rest of the world)
Each system requires a double waterproof socket and a commando style socket for the seawater chiller.
The sockets should be ideally to the right hand side of the system and a metre off the ground. We can make a bespoke system for you if needed to fit your space or electric supply.
Associated Questions
How much electric does a shellfish system use?
Our systems use between xxx and xxx
| System | Electric wattage |
|---|---|
| 100 and 150Kg capacity Lobster Pod | |
| 200, 250 and 300Kg capacity Lobster Pod | |
| Crab Pod | |
| Shellfish Tanks | |
| Bivalve Purification small tank | |
| Bivalve Purificaiton large tank | |
| Oyster Pod (8 and 16 trays) | |
| Oyster Pod (24,32 and 48 trays) |
Our Lobster Pod has a unique power cut failsafe but if you have lobster tanks we recommend getting a power cut alarm as without oxygen lobsters and crabs will only survive hours.
We have thought of this problem and the Lobster Pod live storage system for lobster, crab and langoustine will automatically drain the water out of the trays and into the sump in the event of a power cut and the shellfish can survive for days just damp. This clever fail safe will mean you can sleep soundly knowing your shellfish will be fine even if your area is prone to power failure or if there is a big storm.
If your shellfish are in a tank of water if there is a power cut the air pump and recirculation pump will stop working and the animals may only survive a few hours due lack of oxygen.
To prevent this you can add a power failure alarm. They range from £99 to over £3,500 depending on what you want the alarm to do.
It is worth considering Todd Fish Tech patented Lobster Pod to hold your shellfish if your area suffers power cuts regularly.
We manufacture all of our shellfish systems to order.
We operate a strict first come first served policy. A 50% deposit will secure your place in the manufacturing schedule.
Our lead time is approximately 6-8 weeks. This lead time is longer during our busiest months (August – December) and if we have a large order then the lead time can be as long as 4-5 months.
Please get in touch to find out the current lead time.
Sometimes things outwith our control can delay manufacture. Lead times are always estimated and whilst we try our best to meet them this does not form a part of our contract.
Yes. In 2021 the Maritime Fisheries Fund or MFF in the UK has £100M of grants available.
Links to the MFF funding: https://mffs.marinemanagement.org.uk/
England, Wales and Northern Ireland: https://www.gov.uk/guidance/maritime-and-fisheries-fund-mff-apply-for-funding
Scotland: https://www.gov.scot/policies/marine-and-fisheries-grants/
Our products are eligible for a 50% grant. Please check the guidelines for your eligibility and more information of the application process.
If you would like help to apply for the MFF or any other grant for your fisheries project then please contact our Sea-E-O, Errin Todd who is an expert in grant applications.
Other questions we get asked about our Shellfish Holding Systems.
All of our shellfish systems are designed to be turn-key and do not require installation. They are delivered by a pallet courier and you simply need to unwrap them and put them in place then fill with seawater and plug in.
Our shellfish tanks need the frame assembled and pipework connected but we will send instructions and this is easier than assembling flat pack furniture.
Every system comes with a set up guide and operation manual (hard copy and a pdf via email).
Each system needs time to mature before it can be used to its full capacity – please see ‘maturation’ FAQ for more information.
We only use quality materials which are safe for shellfish.
We use polypropylene to make most of our systems which is fully recyclable
We use ABS industrial pipe as it is more robust than PVC and does not go brittle or release toxins at lower temperature.
All electrical equipment is IP rated.
No metals (or treated wood) are used in our systems as they are toxic to shellfish.
A pallet tank can store up to 40Kg of lobster or crab.
We calculate the shellfish capacity of our tank based on the volume of water, the flowrate of water, filter capacity, temperature of the seawater and how much floor space there is. Most shellfish such as lobsters like having their feet on the ground and do not like being piled up. Having shellfish stacked on top of each other leads to stress, physical damage and ultimately lower survival rates.
We have a secret ratio we use to calculate the shellfish capacity and this has been proven to work both by us since developing and manufacturing shellfish tanks since 1998 and by our many customers in the UK, Europe and USA.
When choosing a shellfish storage system it is important to check the carrying capacity, water volume, floor space and filtration. We would recommend a maximum of 40Kg per square metre of floor space e.g. pallet tank size. If you stock more shellfish in this area there will be a deterioration in the quality of your water and livestock. This would also be dependent on having adequate filtration.
Some filters are rated at a particular temperature for the capacity. If a filter is rated at tropical temperatures the biological filter is more efficient because the good bacteria are most efficient at 20 degrees centigrade. We rate our filters’ shellfish capacity based on operating temperatures of 8 – 12 degrees centigrade which is ideal for shellfish but on the lower limit of the optimum for the good bacteria in the moving bed biofilter. Be careful when buying a filter to ensure the capacity at the temperature you plan to operate your shellfish system at.
Your new system should be simply put in position, filled with seawater and plugged in.
The shellfish tanks require the wooden frame to be built but we supply instructions and it is as easy as flat pack furniture.
The state-of-the-art Lobster Pod system can hold multi-species together including lobster, crab species and langoustine. We do not recommend holding multiple species in tanks.
Crab can be muckier due to their habitat, the grounds they are caught on and the bait used. This means the water may need changed more regularly and the filter sponges and socks cleaned more often. If you plan on storing more than 25% of your overall capacity as crab then we would recommend having separate systems as they water quality will adversely affect the lobster. For a short time or if you do not mind doing more water changes and cleaning then this will work okay.
Langoustine prefer lower temperatures at 8 degrees centigrade and this is on the lower end of the optimum 8-12 degrees centigrade of lobster and crab.
If holding multi species put the langoustine in the top trays, then lobster and crab in the bottom trays. This ensures the seawater goes through the filter after the crab and before going through the trays of langoustine or lobster. Crab should always be in the bottom trays unless the whole system is full of just crab.
We think the Lobster Pod is the best system for storing lobster. It is our best seller, has won many awards and has many advantages over tanks.
Holding lobster in tanks takes up lots of floor space. If you stack the tanks it is harder to access. To reach the lobster you have to get wet up to your armpit or use a net or stick which is not ideal. It is difficult to rotate or grade you stock as more lobster are held together. If there is a weaker lobster in a tank it will rarely survive. Because of the larger water volume the pumps used are larger which costs more to run. The larger volume of water requires a larger seawater chiller which has to work harder to chill and costs much more. If there is a power cut the oxygen in the tank is used quickly and your shellfish are at risk.
In our Lobster Pod the largest capacity of shellfish can be held in a small footprint. The trays are easy to access and each tray holds 10Kg of shellfish which is safe to lift. You can remove one tray at a time or drain a full stack or the entire Pod making loading, unloading and packing easier in our Lobster Pod. Grading and stock rotation are really easy with a Lobster Pod. The design is really energy efficient using natural forces of gravity and centripetal force rather than high pressure pumps. It costs less to operate than a tank. The Lobster Pod is insulated and the design reduces heat gain from the air which means less cost for chilling your seawater. In the event of a power cut the water drains to the sump and your shellfish are safe for days.
Either a Lobster Pod or a Crab Pod are ideal for holding crab.
The Lobster Pod is our best seller for crab and is space and energy efficient and allows easy handling of the shellfish and makes stock rotation and grading simple. It can also hold multi species if you also hold lobster or langoustine. The Lobster Pod ranges in size from 100Kg to 300Kg capacity and many of our customers have multiple units.
The Crab Pod is ideal if you are doing larger volumes of crab or work with spiny species such as king crab. The Crab Pod also works well for crab headed to export markets as it can purge and condition the crab ensuring the highest survival rate of any system on the market.
So, if you want to hold lower capacities of crab, multi species of crustacean at the same time, are prone to power cuts or are short of space then the Lobster Pod is the best.
For larger capacities and for crab destined for air freight then the Crab Pod is best.
Give us a call on Tel No 01383 820685 to discuss the best option for you.
Langoustine are happy in either the Lobster Pod if held loose or the Crab Pod if held in ‘prawn tubes’.
Langoustine (also known as Prawns, Nephrops, Dublin Bay Prawns or scampi ) are happy in either our Lobster Pod where they are stored loose in the trays or in the Crab Pod which can hold them in prawn baskets or baskets.
Langoustine can be stored with lobster and / or crab in the Lobster Pod.
Prawns like to be stored at 8 degrees centigrade.
We have designed our unique Lobster Pod shellfish system to fit in a standard garage or container.
The trays easily slide out of the Pod at the front so no access is required from above. Check your access is large enough for the Lobster Pod to fit in. We can make bespoke smaller or lower Lobster Pods to fit your space if needed.
We use a trusted national pallet network to deliver our shellfish systems including the Lobster Pod, Oyster Pod, lobster tanks and bivalve purification tanks across the UK.
The Crab Pod requires a HIAB for delivery across the UK.
The Lobster Pod, Oyster Pod and bivalve purification tanks can be shipped anywhere in the world – please contact us for a quote.
For delivery we package all small parts e.g. air pump, filter media, filter block etc. in boxes and bubble wrap and place this in the filter and sump section. The Pod or tank has recycled cardboard and bubble wrap wrapped around any corners or parts such as pipework. This is then cling wrapped and labelled.
We have worked with the pallet network for a number of years. The team including Linda and Kathryn at our local depot make sure our Pods get to you safely.
We would recommend at least a square metre of floor space for every 40Kg of shellfish.
Our Lobster Pod shellfish stacking system has the largest capacity of shellfish in the smallest footprint. The 300Kg shellfish capacity Lobster Pod only needs 1m x 3.2m of floor space meaning nearly 100Kg per square metre (2.5 times more lobster per square metre than traditional tanks).
Make sure your access is big enough to fit the Lobster Pod through. The Pod is in one unit and cannot come apart to fit through a door.
Lobster can be held for up to six months in our Lobster Pod system, Crab Pod tank or Lobster Tanks without being fed. They will not lose any weight or condition over this time.
If you plan to hold lobster for more than 3 months we recommend using cable ties instead of bands on the claws as the bands tend to perish and can get caught in the recirculation pump.
If you want to hold lobster for longer than 6 months then you will need to feed them but you should hold a lower capacity as the filter will also need to deal with the food waste. Give us a call for more advice.
We have been designing and manufacturing shellfish systems since 1998. Dr Keith Todd has a PhD in Marine Biology and designs all of our systems to ensure happy and healthy fish. Errin Todd has been working alongside the fishing industry since 2002 and enjoys supporting our customers and ensuring they get the best out of their system to help create successful and sustainable businesses.
We believe our shellfish systems are the best. We are the biggest manufacturer in the UK and make shellfish systems which are easy to use and cost effective to buy and operate. We use quality parts and manufacture everything in-house to our own unique designs. The Lobster Pod system is patented proving it is innovative and unique and you cannot buy this anywhere else.
We have lots of satisfied customers who have validated our shellfish systems.
We have won many awards for innovation, manufacturing and our environmental credentials including Fishing News Technical Innovation Award, VIBES (Vision in Business for the Environment of Scotland) Award, Innovator of the year from Women’s Enterprise Scotland and Business Women Scotland, Scottish EDGE, Silver Great British Entrepreneurs Award in manufacturing, Fife Chamber Award, Scottish Chamber Award and runner up in British Chamber Awards.
We provide support and advice to all of our customers and all of our systems have a one year manufacturers’ warranty.
We have a new, larger workshop with a showroom, office and research area which potential customers can visit by appointment to meet our team and see our quality products for themselves before purchasing.
We believe in helping to contribute to a sustainable fishery and as well as manufacturing lobster hatchery equipment for several hatcheries in the UK we also operate our own lobster hatchery to release baby lobsters for fisheries enhancement. We also have a conservation project to breed the endangered crawfish and we continuously invest in conservation and environmental projects and conduct cutting edge research using our new Research & Development area in our workshop.
We are based in Dalgety Bay, Fife, Scotland and employ local people and pay the real living wage. We operate a successful apprentice scheme providing on the job training to a new apprentice every year. We offer work experience to local school and college students. We purchase all of our parts and supplies from UK suppliers where possible and have positive relationships with our suppliers to support the UK economy.
We are continually learning and seek support from Business Gateway and advisors and mentors to ensure we do the best we can for our team and customers.
We do not rent systems.
Sometimes 2nd hand systems are available and several customers have used a finance company to finance their shellfish system. Get in touch if you would like an introduction.
There are often grants available for our products (see grant FAQ).
We do not offer finance ourselves but we can make an introduction to a finance company that a few of our customers have used to finance their Crab Pods, Lobster Pods and Oyster Pods.
We would recommend any customer who is new to bivalve purification attends a Seafish approved training course and we would highly recommend Martin Syvret at Aqua Fish Solutions.
All of our systems come with a set up guide and operation manual.
We are available to support our customers over the phone on Tel. No. 01383 820685 during office hours (Mon – Fri 9am – 5pm) and customers will be given Keith and Errin’s home telephone number for support outwith office hours.
All of our turn key systems come with a set-up guide and operation manual.
We are available during office hours (9am – 5pm Mon-Fri) on Tel. No. 01383 820685 to support our customers. Customers also have Keith and Errin’s home telephone number for out of hour’s emergencies.
We supply water testing strips with each new system and have them in stock.
New customers are given a water sampling kit (water sample bottle, addressed jiffy bag and water sample form). New customers are encouraged to send us water samples especially in the early maturation phase (see Question on Maturation). We test the water in our lab and give specific advice on stocking, water changes and other measures such as buffering the pH. Customers are always welcome to send water samples to us if they need advice on their water quality.
We can test customers’ tap water for chloramines (see FAQ on Chloramines).
All Todd Fish Tech systems have a one year manufacturers’ warranty.
All of our products have a one year manufacturers’ warranty.
We expect our systems to last a lifetime as long as you follow the guidance on cleaning and maintenance. In the unlikely event that you have a problem with your system please get in touch and we can advise you on the best solution.
Bivalve Purification Systems
Our Oyster Pod stacking purification systems start at £4,000 for a 1000 oyster capacity system.
All of our bivalve purification systems are turn-key and include an energy efficient recirculation pump, insulated fibreglass tank with self-draining base or Oyster Pod stacking system, ultraviolet steriliser and flowmeters, baskets or customised trays, hour run meters and seawater chillers (some other systems do not include baskets, hour run meters or chillers – please check the specification).
Please get in touch for a quote.
All Todd Fish Tech systems are validated.
All of our systems are based on the Seafish Industry Authority guidlelines. We meet or exceed these guidelines for example the Small Purification Tank with a 90Kg mussel capacity should have a 25 watt UV and our system has a 36 watt UV as standard.
Bivalves such as mussels, oysters, cockles, clams and razor clams are filter feeders. They can accumulate bacteria and viruses. To ensure that they are safe for human consumption they must be purified (sometimes called depurated) in a specially designed system which uses an ultra violet steriliser to denature the bacteria and viruses.
In the UK bivalves from A class waters do not need to be purified but we would recommend purifying all bivalves for human consumption. Un-purified bivalves cannot be exported to the EU.
Depuration or purification is using a specially designed system with an ultraviolet steriliser to remove (or reduce to low, safe levels) all of the bacteria and viruses which filter feeding bivalves contain.
Operators are required to have a licence from their local council (contact your local Environmental Health Officer) and you may have to do a challenge test. We will support you through this process and promise that all of our systems will pass the test when operated correctly.
The ultraviolet steriliser bulb needs changed every 6 months on purification systems (our systems have an hour run meter to keep a track of the bulbs lifespan which is 4000 hours).
An Oyster Pod bivalve stacking purification system is used to purify oyster, clams, razor clams or cockles so they are safe for human consumption.
All of our systems will purify mussels, oysters, clams and cockles. There are a few advantages of our Oyster Pod stacking systems over the tank systems however these are not recommended for mussels as some may climb out of the trays and those would need to be discarded.
The Oyster Pod is like a block of flats compared to the tanks which are like bungalows. The Oyster Pod takes up far less floor space. The 350Kg tank which purifies 2500 oysters needs 2.4m x 1.4m of floor space compared to the Oyster Pod which can purify 4000 oysters in only 2.4m x 1m. The 2500 oyster capacity tank uses almost the same floor space as a 6000 oyster capacity Oyster Pod.
Another huge advantage of the Oyster Pod is that between purification cycles you need to drain the trays before loading and unloading to prevent the sediment and dirt in the bottom of the tank being disturbed and affecting the bivalves. With a tank this means using a 2nd tank or dumping the water down the drain and siphoning the water taking time out of you busy day. This hassle can be avoided using our Oyster Pod system as the water is drained from the trays into the integrated sump tank at the turn of a valve and then returned to the trays by turning the valve back. This is far more safe and efficient.
The working height of the Oyster Pod is better with less bending and lifting.
Since launching the Oyster Pod in 2019 it has outsold our tanks by about 10:1.
Yes, unless you are operating in a cold room with an optimum temperature.
Bivalves may spawn if they get too warm.
You may need to demonstrate how you can control the temperature of your purification system to your Local Authority Environmental Health Officer (EHO).
We would recommend using natural seawater for your Purification System however you can use tapwater with salt added for your shellfish system if this is not possible.
You should always mix your tapwater and salt in a separate tank and allow it to sit for over 24 hours to ensure the chlorine in the tap water has gassed off and ensure the salt is well mixed.
Chlorine is harmful to shellfish. It bonds with the ammonia produced by the shellfish to create chloramines (see Chloramine question). Make sure any water you use is dechlorinated (and perhaps test for chloramines in your tap water first).
We recommend Peacock Salt which is made for shellfish and contains not just the right salt levels but essential minerals too. Tell Peacock Salt we recommended them when you order.
Although you can use tap water mixed with salt if you can get natural seawater we would use this. You will not have problems with chlorine and it can be put straight in the system saving on the cost and space of a mixing tank. Also, as Scottish folk (and we’re sure the Yorkshire folk would agree!) we would rather use a free resource than have the cost of salt every time you do a water change.
Industry accredited courses are available for the operators of depuration systems and may be a requirement of your local EHO before you can sell purified shellfish. These courses cover more than just the operation of the depuration equipment. We would suggest any customer who is new to bivalve purification attends the Seafish training course and we would highly recommend Martin Syvret at Aqua Fish Solutions.
All of our systems come with a set up guide and operation manual however we refer all of our depuration system customers to the Seafish standard design operation manuals which can be found here Microsoft Word – 9732.doc (seafoodacademy.org) for the vertical stacking system and here Small-scale-shallow-tank-system.pdf (seafoodacademy.org) for the standard depuration tanks.
There are other considerations that are important when building a depuration facility and Seafish guidelines can be downloaded from here How to Build a Shellfish Purification Centre — Seafish
We are available to support our customers over the phone on Tel. No. 01383 820685 during office hours (mon – Fri 9am – 5pm) and customers will be given Keith and Errin’s home telephone number for support out-with office hours.
All of our systems have a one year manufacturers’ warranty.
We will support you though the initial set up and challenge test. We guarantee all of our systems will pass the challenge test.
If you need any help or advice our workshop is open Monday to Friday 9am – 5pm on Te.l No. 01383 820685. Keith, Errin or Laura will be able to offer you support.
Water Quality
We supply water testing strips with each new system and have them in stock.
New customers are given a water sampling kit (water sample bottle, addressed jiffy bag and water sample form). New customers are encouraged to send us water samples especially in the early maturation phase (see Question on Maturation). We test the water in our lab and give specific advice on stocking, water changes and other measures such as buffering the pH. Customers are always welcome to send water samples to us if they need advice on their water quality.
We can test customers’ tap water for chloramines (see FAQ on Chloramines).
Natural sweater has a salinity of 32-35 parts per thousand (ppt).
To test your seawater salinity (saltiness) use a salinity refractometer (which we can supply). We would recommend checking the salinity weekly (and at least monthly).
You put a small drop of seawater on the slide at the end of the refractometer and look through the viewfinder to see the salinity level.
Natural seawater in the UK should be 32-35 parts per thousand (ppt). Canadian lobster can come from areas where the salinity can be as low as 27 ppt, if you are dealing with Canadian lobster it may be worth checking the salinity that your supplier holds them at so you can match the salinity of your holding tank.
If your seawater salinity is too high then add fresh water which has been de-chlorinated or de-chloraminated (see questions on chlorine and chloramines).
If your seawater salinity is too low then add seasalt (we recommend Peacock salt specifically for shellfish)
The salinity can go higher if the system has been running for a while due to natural evaporation. Lobsters can handle a gradual change in salinity but they do not like a big change of more than 5 ppt per day.
Yes, you can use tap water with salt added for your shellfish system.
You should always mix your tap water and salt in a separate tank and allow it to sit for over 24 hours to ensure the chlorine in the tap water has gassed off and ensure the salt is well mixed.
Chlorine is harmful to shellfish. It bonds with the ammonia produced by the shellfish to create chloramines (see Chloramine question). Make sure any water you use is dechlorinated (and perhaps test for chloramines in your tap water first).
We recommend Peacock Salt which is made for shellfish and contains not just the right salt levels but essential minerals too. Tell Peacock Salt we recommended them when you order.
Although you can use tap water mixed with salt if you can get natural seawater we would use this. You will not have problems with chlorine and it can be put straight in the system saving on the cost and space of a mixing tank. Also, as Scottish folk (and we’re sure the Yorkshire folk would agree!) we would rather use a free resource than have the cost of salt every time you do a water change.
Yes, we would recommend using raw seawater if you can as long as it is clean and free from pollutants. Collecting your seawater at high water is recommended and check the salinity if there has been a lot of rain or you are collecting on an estuary.
If you can’t get seawater then tap water with a salt mix is okay (see question on using tap water).
Yes.
The chlorine bonds to the ammonia that the shellfish naturally produce to create chloramines. Chloramines can’t be gassed off like chlorine and they build the ammonia levels in the seawater to high levels as the biological filter can’t break the bond to consume the ammonia.
Chlorine also affects the good bacteria in the moving bed biofilter.
If you are using tap water mixed with salt then you should do this is a separate tank and ensure you gas off the chlorine for at least 24 hours before putting it in the shellfish tank.
Chloramine is a mix of chlorine and ammonia and is used by many water authorities to kill bacteria and viruses in tap water to ensure it is safe for drinking. Chloramines degrade slowly and can remain active in tap water for many weeks whereas chlorine on its own will degass and come out of the water over a period of about 24 hours.
Chlorine is used to disinfect tap water to ensure it is safe to drink. In some areas chloramines are added to the water as this is an effective disinfectant if the water is travelling long distances e.g. in very rural areas or in areas where so much water is being used it needs to be disinfected quicker e.g. big cities.
Some water authorities add chlorine, some add chloramines and some swop between the two. The change to chloramines often happens when lots of water is likely to be used e.g. the big episode of Coronation Street or the Cup Final or if there has been very little rain or very heavy rain. The water authority do not need to tell you which treatment they use or if they change it.
Sometime the water authority adds chlorine only but this bonds with naturally occurring ammonia (most animals produce ammonia including humans) to create chloramine.
You can ask your local water authority but often the customer service advisor does not know.
There are many things which can cause high ammonia levels including:
A new system which is yet to mature so the good bacteria in the moving bed biofilter are not yet removing enough ammonia.
A system that has been operating for several weeks but uses artificial seawater that has chloramines that were not dealt with when the artificial seawater was made up. This will seriously reduce the growth of the filter bacteria.
Too much stock in the system – overloading the capacity for the system is not recommended.
Shellfish release more ammonia in the first 24 hours.
New stock in the system which were either from muddier fishing grounds, held on the deck for a long time or caught in rough seas or on a hot and sunny or windy day which caused them to be stressed and then release more ammonia.
Shellfish which have been out of the water for a long time which release lots of ammonia on re-immersion, this can be a big problem with Canadian lobster after airfreighting.
Shellfish which have been in a vivier or air freight. Shellfish release lots of ammonia when stressed or they’ve been out of the water for a while.
You should regularly check the ammonia levels in your shellfish system. We would recommend doing this weekly or if you notice any changes such as unexplained stock losses or discoloured or smelly water.
We would recommend following the advice for maturing your system for new tanks and Pods (see maturation question). During the maturation phase the ammonia levels can be high as the good bacteria have not grown and multiplied enough to deal with the ammonia produced by the shellfish.
The easiest way to reduce the ammonia levels is to do a sea water change. If the ammonia levels are only slightly high then a 20% water change may be enough however if the ammonia levels are really high you may need to do a 50% or even 100% water change.
If you have stock in the tanks, are in the maturation phase and cannot do a water change or cannot get enough seawater to do the change then there are some products on the market which can bind the ammonia. These products should be used according to the instructions. They can usually be bought from a good pet shop. They are a short term fix as the chemicals will break down over time and release the ammonia back into the seawater. The only way to really fix the issue is with a water change.
Be aware if you are using tap water with a salt mix as this can lead to issues with chloramines if the chlorine and ammonia mix (see Chloramine question).
If you have any issues please get in touch for advice on Tel. No. 01383 820685.
Over time the shellfish and good bacteria will use the oxygen in the seawater and the carbon dioxide they produce will affect the acidity or pH of the seawater. The pH should be 8.2 however over time this will decrease (become more acidic). Seawater will naturally buffer some of this carbon dioxide but this is limited and to maintain a suitable pH in a shellfish system it is necessary to buffer it artificially.
It is important that you regularly test for pH and if this gets too low you can either do a water change (which we’d recommend every 4-6 weeks) or you can add bicarbonate of soda.
Maintaining a pH as close to 8 or 8.2 as possible will really make a difference to the condition and health of your shellfish.
If you want advice on the correct amount of bicarb to add please give us a call on Tel No 01383 820685. As a rough guide a half a cup of bicarb every couple of days in a 300Kg shellfish capacity Lobster Pod works for us but every situation can be different.
It is better to add small amounts of bicarb regularly rather than a large amount once a week. Shellfish do not like quick changes in the water chemistry.
