Aquaculture Building and Caring for a Miniature Aquaponics System

INTRODUCTION Aquaponics is a method of sustainable agriculture that uses the symbiotic relationships between fish, beneficial bacteria, and plants to grow food. Iowa State University has conducted research and extension programs on aquaponics for several years, evaluating production methods, plant and fish species, lighting technology, food safety, economic feasibility, and sustainability. Although this research has advanced the aquaponics industry as a whole, the cost of the systems and the newness of the technology presents challenges for adoption by the general public. Therefore, a small- scale system was devised that could meet the needs of the public and be used to increase awareness of the aquaculture industry.

A miniature aquaponics system can serve as a learning tool for Figure 2. Miniature aquaponics system. hobbyists, educators, and potential commercial producers. Because The miniature aquaponics system aquaponics is a self-contained described in this publication was ecosystem in which each of the built using readily available and components are co-dependent, there cost-effective materials to promote are opportunities to learn about the adoption by the general public. This complex natural processes that occur benchtop system is fully functional, in the environment. These systems and can be used to produce food provide an opportunity to improve and learn the aquaponics production student involvement in the science, concepts that can be scaled-up to technology, engineering, and math larger, more robust systems, thereby (STEM) fields by providing a model advancing public education and Figure 1. Concept of miniature system for interactive learning. adoption of sustainable aquaculture aquaponics system. practices. FA 0014 October 2017 Aquaculture

BUILDING A MINIATURE AQUAPONICS SYSTEM MATERIALS NEEDED: 1. 1, 12-gallon clear tote with hinged lid 2. 1, black polypropylene bus tub 3. 1, 80 GPH submersible water pump 4. 1, indoor 24-hour outlet timer 5. 1 foot, 5/8” O.D. PVC clear vinyl tubing 6. 1, hydroponics fitting kit with adapter 7. 1.5 cubic feet, clay pebbles (may be supplemented with lava rock) 8. Seeds of choice (leafy greens or Figure 4. Cutting access holes. (Photo credit: Shelly O’Neal, Linn County Extension) herbs preferred) TOOLS NEEDED: HOW TO BUILD IT: 9. 5, 1-3 inch goldfish (or freshwater 1. Cordless drill with adjustable bit STEP 1: CUT HOLES fish of choice) 2. Power extension cord FOR PLUMBING IN LID OF 10. Fish food 3. 2 inch hole saw BOTTOM TOTE 11. 10 gallons of water 1. Using the 2 inch hole saw, cut 4. 1 inch drill bit or hole saw (sized 12. Water conditioner two holes in each lid flap of the to match hydroponic fittings) bottom tote. 5. Reciprocating saw, jig saw, or OPTIONAL MATERIALS: 2. Holes should align with the large hack saw 1. Growing lamp squares in the plastic lid grid at 6. Box cutter blade or knife 2. Light stand or hanging brackets one end of the tote. 7. Measuring tape or ruler 3. Tank stand 3. These plumbing holes will allow 8. Marker 4. Aquarium heater access for the hydroponic fittings in the top tote.

STEP 2: CUT SMALL ACCESS DOOR IN LID OF BOTTOM TOTE 1. Place the top tote crosswise on the bottom tote over the plumbing holes cut in Step 1. 2. Use a marker to draw a straight line across one of the lid flaps from the center crease to the hinge. 3. Using a saw, cut along the line until the access door swings independent of the rest of the lid. 4. Use a flat piece of metal or knife to scrape off the excess waste material from the cut.

Figure 3. Required building materials. (Photo credit: Shelly O’Neal, Linn County Extension)

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Figure 5. Cutting access door. (Photo Figure 6. Drilling holes for hydroponic Figure 7. Assembled hydroponic credit: Shelly O’Neal, Linn County fittings.(Photo credit: Shelly O’Neal, fittings.(Photo credit: Shelly O’Neal, Extension) Linn County Extension) Linn County Extension)

HOW TO BUILD IT: STEP 3: MARK AND DRILL 4. The nipple and open ends of the STEP 1: CUT HOLES PLUMBING HOLES IN BOTTOM hydroponic fitting should be on the FOR PLUMBING IN LID OF OF TOP TOTE bottom side of the tote, and should BOTTOM TOTE 1. With the top tote in position over match up with the plumbing holes 1. Using the 2 inch hole saw, cut the top of the plumbing holes, use cut in Step 1. two holes in each lid flap of the a marker to mark the hole positions bottom tote. on the bottom side of the top tote. STEP 5: CONNECT PLUMBING 2. Holes should align with the large 2. Flip the top tote over and ensure TO THE SHORT HYDROPONIC squares in the plastic lid grid at the circles are visible and in the flat FITTING NIPPLE AND one end of the tote. portion of the tote’s bottom surface. INSTALL THE WATER PUMP 3. These plumbing holes will allow 3. Mark an “X” across the diameter of IN BOTTOM TOTE access for the hydroponic fittings the circles just marked to find the 1. Using a ruler, mark a nine-inch in the top tote. center point. length of 5/8 inch diameter tubing, 4. Use the 1 inch drill bit to cut and cut it at 90 degrees straight Figure 8. Installed hydroponic fittings. across. This length of tubing should (Photo credit: Shelly O’Neal, Linn STEP 2: CUT SMALL ACCESS through the top tote in the locations County Extension) DOOR IN LID OF BOTTOM TOTE marked by the “X”. Do not to drill be appropriate to connect the pump 1. Place the top tote crosswise on the too quickly or carelessly, the holes to the hydroponic fittings in a bottom tote over the plumbing should be a perfect circle to prevent straight line; adjust accordingly. holes cut in Step 1. leakage around the plumbing seals. 2. Attach the tubing to the short 2. Use a marker to draw a straight line hydroponic fitting by sliding the across one of the lid flaps from the STEP 4: ASSEMBLE HYDROPONIC tubing over the nipple. center crease to the hinge. FITTINGS IN TOP TOTE 3. Align top tote on top of bottom 3. Using a saw, cut along the line 1. Remove the hydroponic fittings tote and insert the tubing through until the access door swings from their packaging and one of the plumbing holes. independent of the rest of the lid. disassemble the fittings. 4. The bottom section of tube will 4. Use a flat piece of metal or knife to 2. Insert the fitting ends with the attach to the pump using the scrape off the excess waste material strainers and rubber gaskets on appropriate size nipple attachment. from the cut. the inside of the top tote. The fit 5. Place suction cups to the bottom of should be tight, and may require the pump and attach the pump to threading them in. the bottom of the bottom tote. Figure 9. Pump attached to tubing. 3. Thread on the nuts of each (Photo credit: Shelly O’Neal, Linn respective fitting and hand tighten. County Extension)

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STEP 6: INITIAL SET-UP STEP 10: SOW THE SEEDS 1. This system will be heavy when 1. Add the seeds to the top container it is installed. Start by placing the according to the directions on bottom tote in a sturdy location the seed package. Generally, that can get wet, and can support leafy greens and herbs should up to 100 pounds. Ensure that be sprinkled on top, and larger this location is easy to access vegetable seeds should be sown for maintenance and has access at a depth of 1-2 inches. to electricity for the pump and 2. Seeds should begin germinating supplemental lighting. within the first week for most 2. Reassemble the top tote on the plants. Smaller seeds tend to bottom tote, connect the pump Figure 11. Growbed media. Lava rock germinate faster than large seeds. (left) and pebbles (right). (Photo credit: and tubing. Shelly O’Neal, Linn County Extension) STEP 11: ESTABLISH THE BIOFILTER 2. Make sure the hydroponic fittings 1. The biofilter is made of beneficial and strainers are secure before bacteria that grows on the pebbles adding the pebbles. Once the in the top tote and on the sides of pebbles are added they may clog the tank. This bacteria performs uncovered pipes. the critical job of converting 3. If using multiple types of rocks toxic chemical into plant food. (e.g. lava rocks and clay pebbles), Beneficial bacteria takes 2-6 weeks add the large rocks first, then top STEP 9: ADD WATER to establish. Adding water or gravel dress with the smaller pebbles. CONDITIONER from an established aquarium can 1. Tap water does not provide a help speed up the process. STEP 8: ADD WATER TO THE healthy environment for fish so 2. Small amounts of fish feed in the SYSTEM, START THE PUMP, it must be treated before fish are water every couple of days will give AND SET THE WATER LEVEL added to the system. To do so, fill the beneficial bacteria what they 1. Pour approximately 10 gallons of the container with approximately need to grow. Add a pinch of fish clean water into the bottom tote. 10 gallons of room temperature tap food 2-3 times per week for the 2. Plug in the pump and watch to water. Add the appropriate amount first month, prior to adding fish. make sure the top tote fills with of water conditioner (required water and drains properly. for city water) and bacterial Figure 10. A system with a 3. The water level in the top tote supplements (optional) for 10 supplemental light. (Photo credit: should be about 1/2 inch below gallons of water as described on Phillip Pfister, Linn County Master the bottle. Gardener Program) the top layer of rocks. Too much water can make the seeds rot. 2. Fish should not be added Too little water will prevent them immediately, because the biofilter STEP 7: RINSE CLAY PEBBLES from germinating. Depending on is not yet established. If fish are AND ADD THEM INTO THE the type of hydroponic fitting added immediately, the water TOP TUB used, either the height of the should be exchanged at two 1. The clay pebbles are covered with fitting or the height of the rocks gallons per day for the first two dust that will make the water can be altered. weeks. Fish should not be fed murky. The pebbles should be 4. Plug the pump into the timer, for the first week, with limited rinsed with water before being making sure the timer is set to feeding for the first month. Follow added to the top tote. Flush them turn on and off every 30 minutes. the feeding directions provided with water until the outflowing on the fish feed packaging for water runs clear. further instruction.

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STEP 10: SOW THE SEEDS Table 1. Water quality recommendations. 1. Add the seeds to the top container Dissolved according to the directions on Temperature Ammonia Nitrite Nitrate Oxygen pH the seed package. Generally, (°F/°C) (mg/L) (mg/L) (mg/L) (mg/L) leafy greens and herbs should be sprinkled on top, and larger > 5.0 6.5-7.0 70-80 / 21-27 < 0.1 < 0.1 > 40 vegetable seeds should be sown at a depth of 1-2 inches. 3. Excess fish food degrades water ideal ranges for each of these 2. Seeds should begin germinating quality for fish. Remove any excess water quality components. See within the first week for most feed 15 minutes after feeding if fish ISU Extension and Outreach plants. Smaller seeds tend to are present. If no fish are present, publication “Water Quality germinate faster than large seeds. clean the feed out twice per week Management for Recirculating to prevent fungus from growing. Aquaculture” (FA 0003A) STEP 11: ESTABLISH 4. Monitoring water chemistry is the (https://store.extension.iastate.edu/ THE BIOFILTER only way to know if the biofilter product/14271) for more detailed 1. The biofilter is made of beneficial is established. Once low levels information. bacteria that grows on the pebbles of ammonia and nitrite and high 2. Water chemistry test kits can be in the top tote and on the sides of levels of nitrate are measured, then purchased at a local pet store or the tank. This bacteria performs the biofilter is functioning and fish online. Follow the manufacturer’s the critical job of converting can be safely added. instructions to obtain the levels toxic chemical into plant food. for each parameter. Beneficial bacteria takes 2-6 weeks STEP 12: MONITOR 3. Be sure to record track to establish. Adding water or gravel WATER QUALITY measurements over time. from an established aquarium can 1. Dissolved oxygen, pH, temperature, Changes in water chemistry help speed up the process. ammonia, nitrite, and nitrate are trends can help monitor progress 2. Small amounts of fish feed in the all important water chemistry and predict issues before they water every couple of days will give factors that affect the plants, fish, arise. Create a data log or use one the beneficial bacteria what they and bacteria in an aquaponics available online. One example need to grow. Add a pinch of fish system. It is important to monitor can be found in ISU Extension food 2-3 times per week for the them just as they would be in an and Outreach publication first month, prior to adding fish. aquarium. Table 1 defines the “Water Quality Management Monitoring Sheet” (FA 0003C) (https://store.extension.iastate.edu/ product/14273).

Figure 14. Commercial water chemistry kit.

Figure 13. Nitrogen cycling timeline.

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STEP 13: ADD FISH TO 3. When the fish get home, it is to their new home for a couple of THE SYSTEM a good idea to add more water days before trying to feed them 1. Fish should be added after the conditioner to the water just in to keep from degrading the water biofilter has been established case. The bag of fish should be quality with uneaten feed. Uneaten to prevent unnecessary losses floated in the bottom tote for feed produces toxins like due to poor water chemistry. It 10-15 minutes to allow the fish ammonia that can kill the fish. is typically safe to add fish after to acclimate to their new water 2. Check water quality before trying the system has been cycling four temperature. It is also beneficial to feed fish. If the parameters meet weeks or more. to slowly add your system water the recommendations in Table 1, 2. When choosing fish to add into (using a cup at a time) to the proceed with feeding. an aquaponics system, make bag of fish to acclimate them 3. Once the fish are settled, add a sure they are healthy. Look for to the new water quality. After pinch of feed to see if they are erratic swimming behavior, sores acclimation, the fish can be hungry. If they eat, add more feed or lesions, bulging eyes, and added to the aquaponics system. a pinch at a time until they are no external parasites. Even fish that However, it is wise to remove longer interested, or for up to 15 appear healthy can be carriers the fish from the bag with a net minutes. If they do not eat, stop of disease and become sick once and place the fish in your system feeding and remove the excess they become stressed in the rather than pouring the bag water feed after 15 minutes to prevent transport process. Even with the in, because some diseases can be water quality issues. Some fish best handling methods, fish may transported in the water. are shy feeders, and may not feed still die—don’t be discouraged! in bright light or if they can see More information can be found STEP 14: ADD FISH FOOD AND movement—be patient. in ISU Extension and Outreach MONITOR WATER QUALITY 4. Continue this process of testing publication “Fish Health 1. Transporting fish is a stressful water quality weekly, and Considerations for Recirculating process for the fish, and therefore checking the fish’s desire to Aquaculture” (FA 0001A) the fish probably will not want eat at every feeding. More (https://store.extension.iastate. to eat right away. Fish should be information on feeding can be edu/product/14263). allowed to become accustomed found in ISU Extension and Outreach publication “Feeding Practices for Recirculating Aquaculture” (FA 0002A) (https://store.extension.iastate. edu/product/14267).

STEP 15: MAINTAIN THE SYSTEM 1. The fish food makes the plants grow, so it must be continuously added to the system. Fish food means waste buildup in both the fish tank and the plant container. Cleaning the waste out of the bottom tank and off the pump should be done weekly, or more Figure 15. Feeding fish often if necessary.

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2. Water removed after cleaning, through evaporation, or as Figure 16. Lettuce harvested from transpired by plants should be an aquaponics system. replaced as needed. Water levels in the fish tank should remain above the half-way mark, but below the three-fourths water level, or at a depth of 6-9 inches. Be sure to condition the water with the treatment and allow it to reach room temperature before adding it to an aquaponics system. 3. Plants may show signs of nutrient deficiency of there aren’t enough provided in the feed. Iron is commonly lacking in the water, therefore a chelated iron (e.g. Fe-EDTA) should be added at a AQUAPONICS RESOURCES rate of 2 mg/L every two weeks. Iowa State University Fisheries Extension www.nrem.iastate.edu/fisheries STEP 16: HARVEST PLANTS Aquaponics Youtube Playlist 1. Once plants have grown to a https://www.youtube.com/watch?v=xAudq28n8l0&list=PLyDHx- harvestable size, it’s time to harvest rmZpCljgr4za05H2eHKwmMhJYI1 and try the produce. Some plants grow back if harvested properly, Aquaponics System Design and Management especially leafy greens and herbs. www.extension.iastate.edu/forestry/tri_state/tristate_2014/talks/PDFs/ Pick lettuce one leaf at a time Aquaponic_System_Design_and_Management.pdf from the outside to the inside, An Overview of Aquaponic Systems: Hydroponic Components leaving the small leaves in the https://store.extension.iastate.edu/Product/15111 middle to keep growing. Harvest SRAC Aquaponics herbs from the top, leaving a few https://srac-aquaponics.tamu.edu leaves and branches down low for the plant regrowth. AQUACULTURE RESOURCES Iowa State University Fisheries Extension http://www.nrem.iastate.edu/fisheries North Central Regional Aquaculture Center www.NCRAC.org Southern Regional Aquaculture Center http://srac.msstate.edu ISU Extension Store (search: Aquaculture) https://store.extension.iastate.edu/ProductList?Keyword=aquaculture

Written by D. Allen Pattillo, aquaculture specialist, ISU Extension and Outreach, and Sophia K. Rotole, student in agricultural engineering, Iowa State University.

This institution is an equal opportunity provider. For the full non-discrimination statement or accommodation inquiries, go to www.extension.iastate.edu/diversity/ext.

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