What is Aquaponics ?

Aquaponics is an integrated system that combines hydroponics and aquaculture. In an aquaponics system, the waste water from aquaculture subsystem is used to fertilize plants, and the plants reduce nutrient levels in the water.

What can it Provide me?

Fish such as Tilapia will grow out to provide a 5000kg/cent in a period of 9-12 mnths, when fed properly. Other species can just as easily be grown and harvested for profit too, like bluegill, koi, trout, bass, catfish, perch or even prawns.

Why is it Considered Sustainable?
  • Waste from fish is used to feed the plants.
  • Fish and plants create a polyculture producing two products.
  • Water is re-used in the re-circulating system.
  • Local food production, enhances the local economy and reduces food transportation.
  • Continuous organic fertilizer.
Aquaponics Components
  • Fish Tank
  • Place to Grow Plants
  • Water Pump(s)
  • Air Pump
  • Irrigation Tubing
  • Water Heater (Optional)
  • Filtration (Optional)
  • Grow light (Optional)
  • Fish and Plants

Safe Materials

Make sure all your system components are fish and human safe

  • Polypropylene – labeled PP
  • High Density Polyethylene – labeled HDPE
  • High Impact ABS (Hydroponic Grow Trays)
  • Stainless Steel barrels
  • EPDM or PVC (poly vinyl chloride) pond liner (make sure its UV resistant and avoid fire retardant material)
  • Fiberglass tanks and grow beds
  • Rigid white PVC pipe and fittings, black flexible PVC tubing, some ABS
Fish inputs and outputs

Inputs: Feed Oxygen and Water
Outputs: Urine (water), Ammonia, Carbon Dioxide, Feces, Uneaten Feed

Keeping Fish Healthy
  • pH – Most fish like pH between 6-8
  • Ammonia and nitrites are very toxic to fish
  • Nitrates are fairly safe for fish (and great for plants)
  • Fish need oxygen (they can die in 30 min. without it)
  • Battery based aerators are available for power outages
  • Drastic temp changes can cause health issues and death
  • Sensitive to light (avoid direct light)
Importance of Temperature
  • Do not exceed temp changes of more than 3F per day if possible
  • Fish can not regulate their body temperature like humans do
  • They are dependent on the water temperature for their body temperature
Temperature and growth rate
  • CMAX= Max. feeding rate
  • SDA = Digestion (specific dynamic action)
  • F = Feces, urine production (egestion)
  • U = Ammonia production (excretion)
  • B = Change in fish weight
  • Opt. coolwater temp. = 23 C (73 F)
  • R = Respiration
  • Max. = 28 C (82 F; starvation)
  • Coldwater fishes = 14-16 C (57-61F)
  • Warmwater fishes = 28-30 C (82-86)
Fish Feeds
  • Commercial fish feeds contain exact protein, carbohydrate and other vitamin requirements for specific fish
  • Plant based proteins can include soy meal, corn meal, wheat meal etc…
  • Most commercial feeds are between 10 to 35% protein
  • Alternative feeds should be considered like duckweed, insects, worms or black soldier fly larvae
  • Avoid fish meal based feeds as this source is not Sustainable
Feed conversion ratios

The average pounds of feed to produce 1lb of product

  • Fish – 1.7lbs
  • Chicken – 2.4lbs
  • Turkey – 5.2lbs
  • Pork – 4.9lbs
  • Lamb – 8.0lbs
  • Beef – 9.0lbs
The Bacteria
  • 50% of fish waste is in the form of ammonia released through urine, fecal matter and gills.
  • Bacteria consume fish waste, decaying plant matter and uneaten food.
  • Bacteria nitrosomonas converts Ammonia (NH3 or NH4+) to Nitrite (NO2-) – Nitrite is toxic to fish.
  • Bacteria nitrobacter converts Nitrite (NO2-) to Nitrate (NO3-) Nitrate is primary source of plant nutrition.
  • Nitrogen is the good stuff – it is relatively safe for fish and great for growing plants.
Bacteria (Nitrification) Cycle
  • Rising Ammonia for 10 days
  • Then Nitrite levels rise and Ammonia levels fall
  • Another 10 days, Nitrate levels rise, Nitrite levels fall
  • Total 20-30 days to Stabilize

Bacteria Maintenance
  • Proper pH 7 – 8
  • Best temperature 72 – 75* (ideal 77*)
  • No pesticides, algaecides, chlorine, chlorimine, cleaning agents or chemicals
  • Started with a fishless or fish cycling
Starting the Nitrification Process

Fish cycle

  • Run the fish tank with chlorine and chloramine-free water for a few days
  • Make sure all components are functioning properly
  • Add fish at 20% of stocking density (Aquarium stocking density is commonly 1” per gallon)
  • Keep fish food to a minimum for the first 10 days
  • Monitor water quality and fish behavior
  • Add 20% more fish every 4-6 weeks for best outcome

Fishless cycle

  • Use commercial ammonia tablets and bacterial supplement
  • Use worm tea made from worm castings
  • Use pond or stream water (with caution)
  • Use the filter pad or water from someone’s aquarium
  • Use feeder goldfish (they may not live very long)
System Startup Checklist
  • Decide on type and size of system to build
  • Draw designs, research where to get parts, plan
  • Buy and assemble components
  • Start plants from seed or find source for seedlings
  • Fill system with water and circulate (at least a week)
  • Add plants to system and watch them grow
  • If using a fishless cycle, begin nitrification process
  • Add fish to system about 20% of stocking density
  • Monitor water quality, partial water changes as needed
  • Maintain system
Media system calculations
  • Ideal Grow bed volume to fish tank volume ratio typically 2:1
  • Can go up to 3:1 or as low as 1:1
  • Ideal grow bed depth is 12”
How do you calculate the volume?
  • Determine cubic feet of the grow beds and fish tank (Length x width x height)
  • Convert to Gallons by multiplying cubic feet x 7.48
  • 1 cubic foot = 7.48 Gallons
Example Scenario
  • You have a 50 Gallon fish tank. How do you determine the size of your grow beds using the 2:1 ratio
  • Following the 2:1 grow bed to fish tank ratio you will need approximately 100 gallons of grow bed volume
  • Divide 100 gallons by 7.48 to determine cubic feet Cubic ft = 14’ (rounded up)
  • Assuming ideal grow bed depth of 1 ft you can conclude that a single 2’ x 7’ grow bed would work Or two 2’ x 3.5’ grow beds
  • If depth is 6” you can double the grow bed area to 28 s.f.
Fish Stocking Density
  • .25lb fish per gallon (conservative) to .5lb per gl (moderate)
  • Important to know final grow out weight of fish to determine appropriate stocking density
  • Tilapia avg harvest size = 1.5lb (from UVI data)


  • Tank size = 300 gallon
  • Total fish weight = 300 x .25lb = 75 lbs
  • Number of fish = 75lb/1.5lb = 50 fish
  • Startup fish at 20% total capacity (50 x 20%) = 10 fish
Fish Feeding
  • On average, fish eat about 1.5% of their body weight daily.
  • If you have 75 lbs of fish in system, multiply 75lbs x 1.5% = 1.125lbs of fish feed daily
  • If needed, convert lbs to grams (1lb = 454 grams)
  • 1.125 lbs = 510 grams
  • Don’t just rely on the math. Observe your fish eating help determine the proper amount of feed
Pump sizing
  • Pump should cycle total volume of tank water once each hour at the head you are requiring of it for continuous use pumps,If pump is on a 15 minute timer, it should be sized to pump total tank volume in 15 mins (4x)
Aeration sizing
  • CFM cubic ft per minute is a measurement of the volume of air flow
  • PSI is the pressure required to deliver the correct amount of air flow for proper aeration
  • Simple rule of thumb has 1 cfm per 300 Gallons
  • Several different ways to calculate: either per lbs of fish or water volume or per diffuser type etc…
System Maintenance
  • Feed the fish daily, monitor fish health
  • Test water quality (every other day for the first month, then about once a week, then as needed)
  • As needed clean out filter screens, filter tanks (if using), tubing, water pump, growbed media, etc.
  • Check plant health, trim back, harvest or take cuttings
  • Check plants for bugs or nutrient deficiencies
Other Handy Tips and Tricks
  • Always wash your gravel media before putting in the system – otherwise you will get very cloudy dirty water
  • Test the pH of the gravel media you want to use
  • Use vitamin C and an air pump to bubble out chlorine and chloramine from tap water
  • Use worms (red wigglers) in media beds to breakdown solids and reduce anaerobic zones
  • Never use cleaning products, pesticides, algaecides, fertilizers or like substances in fish tanks or grow beds
More Handy Tips and Tricks

If you get aphides on your plants – spray with diluted vinegar and water solution Avoid direct sunlight on fish tanks, cover the top to avoid algae and make fish happy Never change more than 1/3 of water at a time. More than that will destroy the good bacteria in the system.

Cover outdoor plants during a frost, and shade from the scorching summer sun. Make sure you have backup power available for pumps and Aerators

In aquaponics you can grow any fresh water fish that appeals to you. Considerations are that you want to be sure the environment your aquaponics fish are happiest in is one that your aquaponics system can naturally provide. Trout, for example, like water temperatures below 60 degrees. Can your environment consistently provide this? Also be sure that if you are mixing fish species that they have similar living requirements. Do they all prefer the same water temperature, eat the same food, and have the same oxygen requirements? Don’t mix carnivorous fish with herbivores, or you will find that you are just providing an expensive meal for your carnivores. We have found that tilapia, other cichlids such as oscars, pacu, goldfish, and koi all co-exist well together in an aquaponics system.

How many fish can I grow in an aquaponics system?

A good rule of thumb is to stock about 1 lb of aquaponics fish per 5 -10 gallons of water, or 1-2 fish per 10 gallons of water. Never stock more than 1 pound of fish for every three gallons of water.

Does an aquaponics system have an odor?

No, there is absolutely no odor at all.

Can I put fish in my system right away?


What do I feed my aquaponics fish?

Depends on what type they are. Carnivorous (examples – trout, perch and bass) require a feed that has high levels of protein (45 – 50%). Omnivorous fish (examples – tilapia, bluegill, koi and catfish) require a lower protein feed (typically 32% protein). Younger fish require more protein than mature fish.

While we applaud the efforts of those who try to further “close the loop” by producing their own feed (such as cultivating their own Black Soldier Fly larvae, red worms, and duckweed) we still strongly recommend that you feed your fish a professionally formulated feed. This will insure that not only do these aquaponics fish that are in your care receive an optimal diet for their health, but that your plants also get a balanced diet through their waste.

Is there an organic fish feed?

Yes! And we are proud to be the first company in the country to offer it! Our AquaOrganic feed is free of fish meal, GMO’s and soy.

Where do I get the fish for my aquaponics system?

We also sell a variety of tilapia, as well as bluegill and catfish. We work with an extremely reliable, We are happy to supply the fish for your system at a very reasonable price.

How do I keep my fish healthy?

The best thing you can do to keep your aquaponics fish healthy is to feed them a high quality feed and keep their environment as stress-free as possible. There are actually three kinds of stress that affect fish health: physical, chemical, and biological

Our Specialized Aqua Biologist will visit your farm in every 15 Days and give a Check up and Consultation.

What are the types of diseases will affect my fish?

The following types of diseases normally affecting, But However make sure the frequent visit of a Aqua Biologist in your farm for identifying the diseases at early stage.

Bacterial tropical fish diseases. Aeromonas hydrophila lat.: Aeromonas hydrophila other: “Hemmorhagic Septicemia”, “Motile Aeromonas Septicemia”, “Ulcer Disease”, “Red-Sore Disease”
Columnaris lat.: Flexibacter columnaris other: Mouth Fungus
Fin Rot
Fish Tuberculosis lat.: Mycobacterium piscium
Pseudomonas lat.: Pseudomonas

Can I plant in my system right away?

Yes, it is imperative that you do in order for your aquaponics plants to become established so that they are ready to take up nitrates when Cycling is complete and you have added fish to your system.

How many aquaponics plants can I grow?

That depends on the type of plant you are growing, but in general you can plant about twice as densely in aquaponics as you can in a traditional soil-based garden. This is because your aquaponics plants are getting exactly what they need at the root zone (food, water, oxygen) so the plant doesn’t need to send it’s roots out searching for these things. Your limiting factor is really how much light is getting to the plant.

How do I pollinate indoor plants?

You actually only need to worry about pollination if you are either growing plants for their fruits and vegetables, or your are saving the seeds from your plants. If you are doing either of these, then you will need to understand which pollination category your plants fall into.

What happens if I see bugs on my plants?

First, you are to be congratulated for your careful observation! One of the first rules of pest management is to be constantly looking out for harmful bugs. Second, identify what bugs you are dealing with. Most bugs (especially aphids) can be eliminated by simply spraying them off with a water jet. If your plants are small you can also try removing them from the media and letting them soak in the fish tank for at least 15 minutes. This drowns the bugs, and the fish get a treat. If neither of these techniques works we recommend an organic insecticidal soap/spray. Avoid any non-organic pest control treatment, as well as organic products containing Neem and Pyrethrum. Both are toxic to fish. And with any spray, no matter how safe, avoid spraying over the fish tank or rafts.

Aquaponics Cycling

Bacteria are the carburetor of an aquaponics system that takes the otherwise unusable fish waste and creates a near perfect plant fertilizer. In this article I will demystify the process of establishing a beneficial bacteria colony in your aquaponics system. This process is often called system “cycling”. By the end of this article you will fully understand what you MUST do to initiate aquaponics cycling and to ensure its success. You will also understand what you CAN do to both make the process less stressful for your fish and your plants, and to speed up the process.

What is Aquaponics Cycling?

Cycling starts when you (or your fish) first add ammonia to your aquaponics system. Ammonia (chemical formula NH3) is a compound made of nitrogen and hydrogen. It can come either from your fish or from other sources. Ammonia is toxic to fish and will soon kill them unless it is either diluted to a non-toxic level or converted into a less toxic form of nitrogen. In addition, nitrogen in the ammonia form is not readily taken up by plants, so no matter how high the ammonia levels get in your fish tank; your plants will not be getting much nutrition from it.

The good news is that ammonia attracts nitrosomonas, the first of the two nitrifying bacteria that are present in the air and will populate the surfaces of your system. The nitrosomonas bacteria convert the ammonia into nitrites (NO2) (the golden line in the chart above). This is a necessary step in the aquaponics cycling process; however, nitrites are even more toxic than ammonia! But there is good news because the presence of nitrites attracts the bacteria we are truly after nitrospira (shown by the green line in the graph below). Nitrospira convert the nitrites into nitrates, which are generally harmless to the fish and excellent food for your plants.

Once you detect nitrates in your water and the ammonia and nitrite concentrations have both dropped to .5 ppm or lower, your system will be fully cycled and aquaponics will have officially begun!

Why do I need testing tools?

API Freshwater Master Test Kit

You must have some way of telling where you are in the aquaponics cycling process – typically a four to six week endeavor. Specifically, you must monitor ammonia, nitrite, and nitrate levels as well as pH so that you know that all these elements are “in range”. If they are not, you may need to take corrective action. This is also the only way that you will know when you are fully cycled and ready to add your fish. Plus, watching the daily progress of the cycling process is fascinating and something you can only see through the lens of a test kit. By the way, once you reach the point that your system is fully cycled, you will need to do much less monitoring than during the cycling process. So get through the cycling process and look forward to reaping the fruits ( or should we say the “fish”) of your labor.

To do their testing, most aquaponic gardeners use our Studpac Aquaponic Master Test Kit. This kit is easy to use, is inexpensive, and is designed for monitoring the cycling process in fish systems.
You will also need a submersible thermometer to measure your water temperature. Temperature affects both the cycling rate and the health of your fish and plants once you are up and running.

What Aquaponic plants can I grow?

We have yet to see a plant that doesn’t grow well in aquaponics, except for perhaps acid loving plants like blueberries. We know of people growing papayas, strawberries, heirloom tomatoes, and cantalope. We even successfully grow typically Herbs and Plants. Experiment and let us know what works for you!

Can I use potted plants/seedlings started in dirt?

Absolutely. Be sure to wash off as much of the dirt as possible and inspect your aquaponics plants closely for insects before adding a store-bought plant to your system.

Can I directly sow seeds into my aquaponics system?

In general, any small seeds that you would sow directly into the ground can be sown directly into a media-based aquaponics system. Examples are salad greens, radishes, and carrots. We have found that larger seeds that you would directly sow in soil (for example, beans, peas, cucumbers) don’t germinate as well . For these we recommend using starter plugs such as Rapid Rooter

How do I Start the Cycling Process?

Once you have your aquaponics system set up and your test kit in hand all you need to do to start the cycling process is add a source of ammonia. Traditionally this has been by adding fish and letting their waste be the ammonia, but we are not a big fan of using fish as an ammonia source. Instead we prefer a technique called “Fishless Cycling” where an external source of ammonia is added to your aquaponics system. Why is this?

Typical Nitrogen Cycle

First, both you and your fish will likely experience much less stress because you will not be trying to keep anybody alive during the process. Second, you can more precisely control how much ammonia is added to your system during the process. For example, if you see that your ammonia level is creeping up to 8 ppm, but no nitrites have shown up yet, just stop adding ammonia for a few days and let the bacteria catch up. You can’t do this with fish!

The practical result of this is that with Fishless Cycling you can fully stock your tank once cycling is complete, versus gradually increasing your stocking levels as is recommended when cycling with fish. This is especially beneficial to those who are growing aggressive or carnivorous fish because they are less likely to attack each other if they are all introduced to the tank at the same time.

How do I Cycle Without Fish?

There are several ways to add ammonia to your system, but honestly the best is to simply purchase our Cycling Kits. They come with all the ammonia you will need to fully cycle the corresponding size tank, powdered seaweed to provide a rich supply of micronutrients to get your plants off to a great start, and detailed instructions.

With Fishless Cycling you can add safely fish to your aquaponics system after your ammonia and nitrite levels drop to zero, or close to it, and you have measurable levels of nitrates. This tells you that both the ammonia converting bacteria (nitrosomonas) and the nitrate converting bacteria (nitrospira) have become fully established and are ready to efficiently process fish waste.

Can I speed up aquaponics cycling?

Unfortunately nitrifying bacteria are some of the slowest growing bacteria in nature, and the cycling process can take as long as six weeks. There are a few things you can do to speed up this process, however.

Temperature – like most microorganisms, nitrifying bacteria multiply more quickly in warmer conditions. Their optimal temperature is between 77-86°F (25-30°C). At 64°F (18°C) their growth rates is decreased by 50%. At 46-50°F (8-10 °C) it decreases by 75%, and stops all together at 39°F (4°C). It will die off at or below 32°F (0°C) and at or above 120°F (49°C).

pH – Bacteria prefer a pH range between 7 – 8. Use hydroponic pH up and down products to keep your pH in this range during cycling.

Oxygen – Nitrifying bacteria are aerobic and will multiply much faster under highly oxygenated conditions. Even if you are cycling without fish be sure to have as much oxygen in your tank water as you would if the fish were there. Think of the bacteria as just another living organism that requires oxygen in your system.

Adding bacteria – You can “jump start” the process by adding bacteria from an existing colony. Good sources of beneficial bacteria are ranked here, leading with the best (the lower you go on the list the more chance you have of introducing a disease into your system):

Media from an existing aquaponics system.
  • Filter material (floss, sponge, biowheel, etc.) from an established, disease-free aquarium.
  • Gravel from an established, disease-free tank
  • Other ornaments (driftwood, rocks, etc.) from an established farm.
  • Squeezings from a filter sponge
  • Rocks from a backyard pond with fish in it.
  • Rocks from a river, lake or wild pond.
When do I add plants?

We recommend adding plants as soon as you have started the aquaponics cycling process. The reason for this is that it gives the plants some time to put down roots and establish themselves before the fish are introduced and nitrates need to be absorbed.

I’ve done all this, but I still don’t seem to be cycling! What could have gone wrong?

Establishing the nitrogen cycle, is the hardest, most frustrating, part of aquaponics, in part because the activity is all invisible to the naked eye. Aquaponics cycling, however, is the most crucial and probably the most difficult part of aquaponics – but it really isn’t that hard if you can be patient! We hope that the nitrifying bacteria are finding our system, and then moving in and reproducing, but the only way that we know what is happening is through sometimes subtle changes of color in a test kit test tube. And when that test tube stays the same color day after day, sometimes week after week, it is very frustrating.

Temperature – During the colder months of the year, this is the number one issue we see, especially with people who are cycling without fish. The optimal temperature for bacteria reproduction is between 77-86 degrees F (25-30 degrees C). At 64 degF (18 degC) their growth rates is decreased by 50%. This means that the rate at which you cycle will be twice as long as it would be with warmer temperatures.
pH Too Low – Bacteria always prefer a pH closer to 8.0. While this is too high for your plants to be happy, during cycling the bacteria are the main focus so targeting a higher pH than you will want during the rest of your system’s life makes sense.As an aside, if you are using the Studpac Aquaponics Master Test Kit, and you see a reading of 6.0 that means that your water is at 6.0 or below. You might want to find another means to test to an even lower range to see what your actual, true pH reading is.
Chlorine – This chemical is added to municipal water supplies for sterilization (i.e.,to kill the bacteria). It is easy to remove because it dissipates from the water as a gas. If you don’t already have a dechlorinating filter on your incoming water supply you can get rid of chlorine by simply holding the water in a separate tank for a day or two. Oxygenating the water using an aerator will speed up the process.
Chloramine – While you can assume your city water supply has chlorine in it, chloramine is more rare. But it is also much more difficult to get rid of. There are two ways that , The first is a double mechanical filtration method where you send the water through both a charcoal filter and a reverse osmosis filter. The second is to remove it chemically by adding a product such as ChlorAm-X. If you are using the chemical method you should do this in a separate holding tank before the water enters your aquaponics system.
Stop Adding Ammonia – The next problem we see only occurs during fish-less cycling, and the scenario unfolds as follows. You add enough ammonia to reach 4.0 ppm then you start testing your system every day. After a while the ammonia disappears and nitrites show up. Good news! The problem starts, however, when you don’t replenish the ammonia. Think of the ammonia as food that you set out to attract the first set of nitrifying bacteria (nitrosomonas), and those bacteria come to the party bringing the food (nitrites) for the second set of bacteria (nitrospira). If the food runs out, the party is over and everyone goes home! You need to keep up a steady supply of ammonia in the front end of the process to keep everyone happily reproducing and colonizing your system. That steady supply can come either from an ammonia compound or from the addition of fish to your system.
Too Much Ammonia – Some aquapons believe that ammonia levels higher than 6 ppm will actually retard the cycling process. Some don’t.
Sterile Environment – Occasionally we find a system that is being started in an indoor environment that is so shut off from outside air and a natural supply of nitrifying bacteria that it will never cycle on its own without the addition of purchased bacteria.
Lack of Oxygen – Nitrifying bacteria are aerobic. The more oxygen you have flowing through your system the faster your system will cycle. Be aware that this is challenged by above. Liquids at higher temperatures have a harder time holding gas, so if you are heating your water to encourage bacteria growth be sure to pump up the oxygen as well.
Time – Cycling is a natural process that we can certainly encourage by establishing favorable conditions, but after that Mother Nature is on her own schedule. You might be doing everything right, and the bacteria just need a bit more time.
You really are cycled; you just don’t know it – It is so easy to fix and the customer is usually delighted to discover that his problem was not really a problem at all!! Aquaponics cycling of a system can be a trying time, but the good news is that once you are fully cycled, you can safely add fish and plants and will never need to go through this again!

Pesticides for aquaponics

The use of pesticides in aquaponics is a very touchy subject, and we’ve seen both the good and bad side of pesticide use in aquaponic systems.

There are many opinions on the subject with varying degrees of validity. Over all of these opinions rules a single fact:

Chemical pest management in aquaponic systems must be approached judiciously, thoughtfully and with caution, whether you are using a homemade remedy or a commercial product.
You must know that this information was hard-won over the course of many years. Let’s talk about the options that you have for using pesticides in an aquaponic system.

Homemade remedies vs. commercial products

Many aquaponic practitioners swear by garlic, chili and vermicompost based concoctions, and to be fair, these can be effective on specific pests. Having tried almost all of the home remedies over the years, these days I rely entirely upon commercial products. This means that we use proven commercial products that have been studied and provide the information necessary to determine their effect on our aquaponic system- products that we know from experience kill and control pests.

Speaking from experience with pesticides

Pests are inevitable in aquaponic systems, and dealing with them has always presented a very difficult dilemma for aquaponic producers, primarily because there are so few pesticides that are non-toxic, or of low toxicity to fish

OMRI certified pesticides

Organic pesticides, most of which are OMRI certified. This is primarily because we, like most commercial AP producers, produce “organic” produce and use pesticides permissible under USDA Organic Standards.

Chemical controls

Use a variety of products that exert chemical control over our greenhouse pests, including:

  • Pyrethrin based products
  • Soaps
  • Azadirachtin based products(extracted from neem oil )
  • Neem oil and neem oil derivatives

*Note: Pyrethrins are very toxic and can only be considered for use in ZipGrow Tower based systems

How to use pesticides safely in your Aquaponics System?

In sump based ZipGrow tower systems, all of these products can be used with minimal concerns, as the system exposure is very limited by the design of ZipGrow towers in combination with a sump. The housing prevents a majority of the overspray and applied insecticide from entering the system solution, with a majority of the excess application running off of the plant leaves and onto the ground.

Calculating lethal dose

In order to do the math, one must understand a special rating called the LD50 or LC50. These represent the median lethal dose or Lethal Dose 50 or Lethal Concentration 50- the concentration at which half of the sample population will die. In regards to pesticides, they are often studied and the LD50 is determined for a certain time period (usually in hours or days).

While it takes some digging, most pesticides have have an LD50 rating, determined experimentally for a variety of marine organisms. Fortunately for many aquaponic practitioners tilapia spp. (Oreochromisspp.) are a common test subjects.

When we look for LC50 numbers we typically go to the source material- scientific publications that detail experiments with different organisms and chemicals, or the Veterinary Substances Database, and use the lowest LC50 published.

For Instance: Pyrethrins

Pyrethrins are a family of very effective insecticides that most aquaponic practitioners cannot use in their systems because they are highly toxic to fish, and most practitioners have no idea how much is safe and how much isn’t.

To discover how much a system can handle, we must look at the LC50 for pyrethrum (type 1 pyrethrin), When we look for this number we find that the LC50 (in 96 hours) for rainbow trout (Oncorhynchus mykiss) is 0.005 mg/L and for aquatic crustaceans is 0.0014 mg/L (96 hrs;Americamysis bahia). Since 0.0014 is the lower number, we’ll use this number.
We need to determine how much pyrethrin is required to hit the LC50 for your system.