Final report for FNC24-1405
Project Information
Ashtyn, CEO of OceanArc, has been raising saltwater shrimp in central Ohio (based out of Pataskala) since graduating college in 2015 from USC. His facilities currently produce 28,000 lbs of shrimp a year in Ohio alone along with other species of fish and crawfish. He is also involved in seafood distribution nationwide (mainly in the Midwest with live lobster, blue crab, crawfish, etc to Asian supermarkets) along with being part of a restaurant group with over 87 restaurants (of which 2 are in Columbus, Ohio alone). Running an aquaculture farm helps market his restaurants and his seafood distribution business.
Dan Wehner is owner of Green Valley Shrimp Farm based in Mount Vernon, Ohio and a new shrimp farmer (and new aquaculture farmer in general). He will assist Ashtyn in evaluating this new raceway design and replicating the design if it looks promising in the beginning. Replicating the design so we have two running models (or more) would allow the team to have more data to support the effectiveness of this new design and take the experiment even further as far as experimenting with other species of crustaceans and fish.
Something that's been on our mind is to how to lower the cost of entry (and cost of expansion growth) in the aquaculture industry. Startup and operating costs are just too high for many fish farms to get off the ground, let alone make a profit in a reasonable timeframe to possibly expand. Though our experiment in this project is geared towards shrimp, it applies to any species of fish/crustacean grown on farms today.
Something on many fish farmers’ minds is how to lower the cost of entry (and cost of expansion growth) in the aquaculture industry. Startup and operating costs are just too high for many to get off the ground, let alone make a profit in a reasonable time to expand. Though our experiment involved rearing shrimp indoors, it applies to any species of fish/crustacean grown on farms today that involves farming infrastructure in tanks/pools.
The two main questions we are trying to solve:
- Is there a better large indoor tank structure that is more durable and professional than a swimming pool, less expensive and easily moveable than fiberglass tanks, less labor intensive and easily movable than a wood frame raceway? These 3 typical options all have issues that are a heavy burden individually, especially for the beginning farmers. See below the pros and cons of these 3 options and our metal frame design.
|
Rearing Tank Type |
Pros |
Cons |
|
Swimming Pools / IBC Totes |
-Cheap/Affordable -Easily Available Locally -Volume Variety from 275 – 6000 Gallons |
-Not professional looking, especially in marketing products farmed in swimming pools -Replace every 1-3 years, more often with spiny fish |
|
Fiberglass Tanks |
-Hardy, last 10+ years -Almost impossible to puncture with spiny fish -Professional look for customers/marketing -Custom design to a farm’s specific needs |
-10-15X more expensive than swimming pools/IBC totes -Expensive and bulky to ship and move within a facility, normally require heavy duty equipment |
|
Wood Framed Tank with HDPE Liner |
-Decently hardy, last 5+ years -Professional look for customers/marketing -Build to custom design needs |
-8-10X more expensive than swimming pools/IBC totes, especially counting labor -Labor intensive to put up and line the liners right |
|
Metal Frame Rectangular Tank Design |
-Heavy Duty, Hard to Puncture Design Meant to Last 10-15 years -Easily Moveable in Sections -Easily Scalable (attach more panels to make longer/wider) to any size -Moderately priced, 5-8X cost of swimming pools |
|
- Is there a more efficient way to heat large bodies of water in the grow out tanks than through the air or through hydronic systems, two methods commonly used? See below the pros and cons of 3 options and our pool heater design.
|
Heating Method |
Pros |
Cons |
|
Gas Fired Commercial Air Heater |
-Heats entire building, not only the water in the tanks -Equipment out of the water |
-Need to heat the air to heat the water, not very efficient |
|
Hydronic Heating System Hooked Up to Boiler/Tankless Water Heater |
-Heats through hydronic PEX tubing wrapped inside the tanks -Very efficient |
-Makes it hard to keep tanks clean and harvest with PEX tubing inside the tanks |
|
Wood Burning Stove |
-Often the most expensive of any option |
-Have to maintain wood feeding the burner. |
|
Hayward Pool Heater (Electric or Gas) |
-Heats water directly, commonly found in aquariums with filtration upstream. -Readily available and affordable |
-Regular maintenance to prevent clogging, need filtration/settling upstream. |
Through this project, we have found that using adjustable metal frame tanks that can accommodate varied sizes/dimensions and be easily moved are worthy middle grounds for new farmers or expanding farmers. The metal frame tanks are more professional-looking and durable than swimming pools or wood-frame tanks with a slightly higher price tag. The metal frame tanks are less expensive and easier to move than set fiberglass tanks.
We have also found that using heat pumps to heat water directly does come with the benefit of a straightforward design to implement compared to hydronic heating, wood burning stove, and gas fired air heating. It also comes with a chilling aspect for those hot summers that other heating methods do not have. However, there are considerations to be made for all heating sources depending on energy costs and availability, and what species one is trying to raise, along with the climate one is building a fish farm in.
We were able to run experiments comparing the grow out of saltwater shrimp in hydronic heated, round swimming pools versus heat-pump heated, rectangular adjustable metal frame raceway. The results showed that both yielded successful, comparable harvests (high survival rates and growth rates).
Even though the energy costs of heating for the rectangular raceways were higher, we believe it is worth it due to ease of harvest and more professional looking setup for marketing purposes compared to the swimming pools. We have shared these observations with other farmers and researchers and so far, we have heard from a new Ohio tilapia farmer they are looking to implement our rectangular raceway design and Bowling Green State already implemented our heater design for aquaponic use. The added benefit of the heater having a chiller option is an easy decision in the summer months when water temperature spikes in their greenhouse.
At our farms and fellow farmers looking to get into the industry or expand soon, this project has already piqued the interest of many to consider using adjustable metal frame raceways and heating/chilling water directly with a heat-pump. Though we were unable to collect data seeing customer sentiment about buying shrimp produced in one way versus another, the thought is the more professional the setup and further away from looking like swimming pools, the better. Especially for a higher priced seafood product.
Metal Frame Raceway Design Drawing
The raceway system will be built out at one of the OceanArc locations in central Ohio and also at the Green Valley Shrimp Farm facility to produce saltwater shrimp indoors. The raceway will measure 10FT W x 40FT L x 3FT H, divided into moveable powder-coated metal panels that are 3FT W x 10FT L each. 10 of these panels bolt together using bolts and screws to build the tank frame which will sit on the concrete floor. This raceway will hold 9,000 gallons of water, effectively replacing the footprint of (3) 14FT DIA swimming pools currently used in most OceanArc facilities.
This system will be more robust and agile than any other build. If we want to make smaller raceways with smaller bodies of water, we can just disconnect two sets of panels opposite each other in the raceway and reconnect the others. If we want to make larger raceways with larger bodies of water, we can just connect additional two sets of panels opposite each other in the raceway and bolt everything together. If we want to move the raceway altogether to a different location for any reason (rented facility no longer accessible, moving the farm, etc), just disconnect everything and move it easily in those straight panels, one by one! Note that the HDPE liner we use is tough enough for us to adjust but easily and cheaply replaceable many years down the road.
In addition, the heating and plumbing system will be upgraded. Instead of using hydronic heating system or heating through the air, neither as efficient as heating the water directly, a Hayward 50K BTU heat pump will be used to heat (and chill, which is an added option in the summer months!) the water directly. The water will be pumped from the pond on one end with a 1HP Hayward pump into the heat pump and then sent back into the pond through the other end through a number of nozzles, effectively creating a continuous raceway in one direction to prevent dead zones.
The above raceway design will function as our “treatment” to see if we can answer the two questions we are trying to solve: if there is a more efficient, durable, and cost-effective fish/shrimp production design for indoor aquaculture and if there is a more efficient and simple way to heat the water specifically in the Midwest, where there are winter seasons to deal with.
For the “control” group, we will use (2) 14’ FT circular swimming pools normally used at OceanArc facilities to compare the performance of how the saltwater shrimp grow compared to how they grow in the “treatment” design.
- Evaluate how well the metal frame raceway design with HDPE liner holds up through several grow out cycles of saltwater shrimp compared to the typical swimming pools used.
- Compare harvest weight and survival rates between shrimp raised in the raceway design and shrimp raised in the swimming pool design.
- Measure temperature daily (preferably continuously if possible) for both raceway and swimming pool designs to test temperature uniformity through the grow cycle.
- Compare energy usage between the raceway design that heats water directly and the swimming pool that heats water through hydronic heat.
- Share findings to fellow farmers and potential farmers through presentation at the Ohio Aquaculture Association Annual Conference.
Cooperators
- - Producer
Research
We were able to set up 30,000 PLs at the two farm locations, one in Mount Vernon and one in Galion on July 10th, 2025.
At both locations, we stocked 15,000 PLs in two separate 275-gallon IBC totes set up as nursery tanks where they stayed for 24 days. We kept the water at 78F, dissolved oxygen above 6.5 mg/l, salinity at 24PPT, and fed Zeigler feed 4-6 times a day with automated feeders. 20 gallons of water was exchanged daily with a mature shrimp grow out tank with mature water (over 2 years old) with salt added in. Unfortunately, for water source and temperature failure issues at the Mount Vernon location, all the of the PLs died within 5 days. Instead we were only able to do the experiment at the Galion farm location. In the future, we will retry the Mount Vernon location on our cost.
All results from this research come from the Galion location under OceanArc Technologies.
After 24 days, there were about 28,000 mature PLs ready to move onto the next stage of grow out. Traditionally, OceanArc has stuck to a 3-stage grow out process (nursery, intermediate, grow out) because historically we've seen better growth and uniformity this way. However, to reduce variables in this experiment, we decided to go straight out to grow out in both our rectangular tanks and round tanks to more easily compare.
We used (2) 15FT round metal frame Intex swimming pools with our traditional PEX heating (wrapped 3 times around the perimeter) and hooked onto homemade 3'' PEX airlifts with 6'' silica diffusers in each. In the center there is a tub with a 1/2'' diffuser tubing wrapped around it. In all, there are 8 total aeration supplies and PEX for heating.
We used (2) 10FT wide x 40FT metal frame rectangular tanks with liner as well. They are both heated by the single Hayward pool heater and the aeration was set up as shown in the diagram.
We calculated the surface area of the 15FT round pools to be 16.5 m2 and the metal rectangular tanks as 37.2 m2. So the metal tanks were 2.25x bigger. We decided to keep the stocking density consistent, so we settled conservatively on 200 mature PLs / m2, which turns out to be 3300 and 7440 respectively. It's hard to count it all exactly but we stocked each round tank with ~3500 shrimp and each rectangular tank with ~7500 shrimp. Leftover shrimp (of about 6000) were put into production elsewhere at the farm but not monitored for this project.
In both cases, we aimed to keep water at 78F, dissolved oxygen above 6 mg/l, salinity at 15PPT, and fed Zeigler feed 2-3 times a day for 67 days. In total, the shrimp has been in farm for 91 days when they were harvested on October 10th. Some of them had to be harvested on October 11th because of labor issues.
We were able to gather this data after harvest:
|
Parameter |
Round Pool #1 |
Round Pool #2 |
Rect. Tank #1 |
Rect. Tank #2 |
|
Harvest Total Weight (lbs) |
117 |
126 |
268 |
196 |
|
AVG Weight/Shrimp |
17.8 |
18.1 |
16.9 |
17.5 |
|
Shrimp Count Size |
25 |
25 |
27 |
26 |
|
Calculated Survival |
2977/3500 |
3153/3500 |
7184/7500 |
5074/7500 |
|
Calculated Survival Rate |
85.1% |
90.1% |
95.8% |
67.7% |
|
Average Water Temp |
76.8 |
77.1 |
77.6 |
77.4 |
|
Calculated Heating Cost |
$22.42 |
$22.42 |
$96.84 |
$96.84 |
Note the following:
- The average weight of shrimp was calculated for each tank by taking 20 samples from each tank during harvest and measured individually.
- To get the calculated number of shrimp survival, we multiplied the average weight by the total harvest pounds.
- To calculate survival rate, we divided calculated number of shrimp survival by the number of shrimp initially placed in each tank at the start of grow out. Multiple x 100 to get percentage
- The heating cost is a little tricky. The round tanks were set up in a gas-powered hydronic heating system with 12 tanks. We added up our gas bill in the months of July, August, and September (since the shrimp were in there July 10th – October 10th) and divided by 12. Our gas bill for those months total was $269 so divided by 12, it came out to $22.42 for the round tanks. For the rectangular tanks tied into the Hayward pool heater, the electric bill saw an increase of $37.03, $41.54, and $45.10 for the months of July, August and September. We added those numbers up ($193.67). Divide it in half, we come to each rectangular tank using $96.84.
The observations from the results are:
- The average weight and size of the shrimp at harvest did not vary much between the two tank systems.
- The survival rates between the two tank systems are really high (>85%), though one rectangular tank showed an outlier at 67.7%. We will need to do more trials to see if this outlier holds up, which I don’t expect it will.
- Average water temperature stayed close to the setpoint of 78F. No major difference between the two tank systems.
- The heating costs associated with the electric pool heater are 5X higher than the hydronic heating system. However, this could be attributed to scale of heating (12 tanks heated together would be cheaper than 2 tanks heated together) or that the pool heater has a chilling function.
- Unfortunately, we didn't time exactly how long it took to harvest. It took us roughly 2hrs to harvest each round tank with 2 people and 2.5hrs to harvest each rectangular tank with 3 people. Remember that the rectangular tanks are 2.25X bigger than the round tanks. So, it took us an extra 25% more labor to harvest 125% more product (assuming survival rates are the same as expected moving forward). This is something we will measure more accurately moving forward, but if this rings true, it would save us a tremendous amount of harvest labor!
Educational & Outreach Activities
Participation summary:
We have shared pictures and our design to a number of fish farmers and aquaculture researchers and extension. Outcomes were shared with the Ohio Aquaculture Association (talk during our annual Conference in January 2026) along with at the USDA-NCRAC annual meeting in February 2026 at Iowa State. We’ve discussed with farmers looking to avoid the price of fiberglass tanks and the unsightly look of swimming pools.
We plan to share our outcomes at the 2026 Kentucky State University Shrimp Farming Symposium in April 2026.
We plan to give tours for those interested in building similar moveable metal tanks and also our heating design. There is a new tilapia farmer in Marysville, Ohio interested in putting our tanks in this Spring 2026. Bowling Green State has copied our heating design for their aquaponic greenhouse setup. BrightFarms has copied our design to grow hydronic lettuce at their New Hampshire facility.
Learning Outcomes
The two main questions we wanted to answer in the beginning of this experiment were:
- Is there a better large indoor tank structure that is more durable and professional than a swimming pool, less expensive and easily moveable than fiberglass tanks, less labor intensive and easily movable than a wood frame raceway?
- Is there a more efficient way to heat large bodies of water in the grow out tanks than through the air or through hydronic systems, two methods commonly used?
Though we were only able to run one trial comparing the swimming pool tanks to the metal frame tanks, it’s reasonable to assume the metal frame tanks will require less maintenance and have longer longevity (10+ years) compared to the swimming pools that many farmers replace every other year. Though the metal frame modular tanks are modestly more expensive, they have advantages over all 3 other forms (swimming pools/IBC totes, single-piece fiberglass tanks, wood framed constructed tanks with liners.
After this experiment, it seems hydronic heating is still more efficient and cost-effective compared to direct pool heaters, the higher heating cost is worth it (in our case) due to it being easier to harvest shrimp in at the end. The components of the metal frame tanks were easily removed to harvest more effectively than in the hydronic heated round pools because the PEX is in the way. However, I believe there are ways to reduce the cost of heating with the pool heater by turning off the chiller function and attaching more tanks to the heating system so the heating bill can be split more than twice.
As far as our five objectives:
- We can reasonably assume our metal frame raceway design will hold up longer than swimming pools. The higher cost in the start looks to be worth the investment to have a professional grow out look (important for marketing in food space) and lasting 10+ years versus 2-3 years.
- The actual production of shrimp (size and survival rate) appear similar in both the rectangular raceway and the swimming pool designs, though one outlier is there for the raceway. It’s reasonable to see 85% survival rates in both systems.
- Water temperature (when set to 78F) stays the same for both tank designs.
- Energy costs were 5x higher for the electric pool heater compared to the gas-powered hydronic heating system. Gas is normally a cheaper heat source than electric. In our case, the ease of heating water directly instead of through PEX made it easier to harvest and keep the system clean. Each farmer will have to evaluate the best option for their situation. For us, heating water directly is worth the higher cost of electric versus gas hydronic heating.
- We will continue to share results with our farmer, extension, and researcher community within Ohio and beyond via farm tours, on-site consultations, phone calls, and various conferences including Ohio Aquaculture Association, USDA NCRAC, and Kentucky State Shrimp Symposium.
Project Outcomes
- Bowling Green State recently added a Hayward heat/chill unit exactly like the one we used to their aquaponic setup, seeing that it keeps the greenhouse water heated to the right temperature year round. The researcher said: "It works great! Much better than the 1/4HP chiller unit they had before where all the fish died when a sensor went out".
- Tilapia Farmer in Central Ohio: "I think I can put this heater after the drum filter in my design to help keep the temperature super high to produce tilapia more quickly"
Definitely consider calling your local metal fabricator to see if they can make these modular tanks locally for you. You can buy the HDPE liner directly online, but try to avoid buying from aquaculture sources, as they seem to pump up the price by adding "aquaculture use" to them. Swimming pools are still the cheapest way to get started but consider modular metal tanks before considering fiberglass tanks, which are more expensive.
Unfortunately, there are many fish farmers going out of business. If someone is determined to start, it would be invaluable to look into used equipment to save on cost of entry. Many fish farmers like myself are more than willing to provide free consultation to help guide them in the right direction.
For these modular rectangular tanks, it would be great to experiment with other species of fish. At OceanArc, we plan to continue farming shrimp and anticipate expanding the use of these tanks to tilapia and holding catfish.