Aquaponics: Vegetables and fish protein – family size

imagesThis is a guest post by Marvin H

I have spent a lot of time researching aquaponics for my daughter. Over several months, I accumulated a lot of information, some contradicting others. From comparing and logical thinking, I have written this article that could be very valuable for anyone considering starting a home system.

Survival is important, but having products to barter in a ‘last case’ scenario is also important. The ease of learning this system and low cost to start and expand the modular program, even to go commercial after several years learning, are valuable alternatives.

There is not cost for this information, so there is no further support by me personally. From the links to hundreds of sources, you will find many willing to take money for consulting.

Please fell free to distribute this if you feel it has value for your community. It could save a beginner a lot of sweat, tears, and money. There is a lot of time, effort, and judgment in the assembly of these sources and most aquaponics gurus (except commercial firms) do not believe anyone should buy the kits offered on the Internet.

The spamming is absurd, yet a search for “Aquaponics” produces over four million hits, so there must be interest.


  • Better tasting vegetables (after well established – up to four years)
  • No chemicals, pesticides, or fertilizers
  • Healthier, fresh vegetables
  • Yearly harvest of fish
  • Self sufficient vegetable supply
  • Minimum effort with no gardening problems when using sealed greenhouse
  • Cheap greenhouse, easily expandable
  • Low water requirement
  • Low power requirement when planned for gravity flow
  • Worms, bacteria, hardy fish, duckweed, simple filters create amazing harvests at low cost


  • Attention more critical for fish care than kids or animals
  • Water quality control biggest error for beginners – pH, oxygen, nitrates, temperature
  • Over feeding and too few plants kill fish
  • Failing to properly cycle new system (up to a month in warm temperature, longer when cold) results in poor water quality, fish shock, and dead fish
  • Power outages without back-up system: high fish mortality (lack of oxygen, too much ammonia)

Beginners, START SMALL with a simple modular system easy to expand

First Module:

Use a food grade IBC container: Australian Faye Arcaro (Backyard Aquaponics – Perth – latitude of San Diego down under) converts an IBC container to a fish tank and one grow bed in good video posted on-line by . This one grow bed, and maybe another later, is a module that can be expanded easily and cheaply. Plan to learn with this module. Do not expand until after two years learning. It can be expensive. With fish costing $1 each, the 100 dead fish in the module being replaced often because of your mistakes while learning gets expensive.

The IBC fish tank should be elevated enough for gravity to drain water to the swirl filter and bio filters, and into a sump tank.

Water temperature control easier and cheaper if fish tank is buried in ground. However, flat land loses advantage of gravity water control for part of cycle.

Filters and Start-Up (for one module – a food grade IBC tank and one grow bed can handle the growth cycle of plants and fish without filters):

Adding filters is easy, cheap, and good insurance.

(1) A swirl filter uses basic physics to do the work. While stirring a solid powder in a cup of water, you will see the particles concentrate in the center. That is what happens in your swirl filter. A plastic container with a sloping bottom (or top upside down) helps the particles gather in the center, which is the drain. A little research on the web will find videos (Google: YouTube Aquaponics “swirl filter”) showing the plumbing and slow water flow for this highly effective filter to remove large particles of fish waste, wasted fish food, and any trash in the nutrient rich water going to plant beds. The filtered waste can be used for worm beds, fertilizer for fruit trees, or other plants in the ground. Design should plan for the fish tank water to flow by gravity to the swirl filter. Particles increase wear on pump.

(2) Biofilter(s): The larger the system, the more critical are filters after the swirl filter. The two types of bacteria critical for the aquaponics system convert ammonia to nitrites and nitrites to nitrates (fertilizer for the plants). These bacteria form colonies naturally. The speed of system colonization is directly related to temperature and surface area in the system – plumbing, bio filters, grow bed media, and fish tank. The process can be speeded up in a new system by starting the cycle using some water from a fish pond, aquarium, or another aquaponics system. Ammonia must be added daily to the system while pH, oxygen, ammonia, nitrite, and nitrate levels are tested regularly (and recorded in your journal).

One method to increase surface area is to use simple filters available at low cost. A plastic bucket with the filters and plumbing (after the swirl filter) before pumping the nutrient water to the plant beds will provide extra protection and increase the work of the beneficial bacteria. Check the web for aquaponics filters. Plain sponges, sand, or cheap home or industrial filtering materials can be used.

Filtering the nutrient water to remove particles reduces the waste build up in the grow beds and helps increase availability of oxygen to the plant roots. An additional natural help keeping the grow bed media clean is to put earthworms in the grow beds. Worms thrive on fish waste. Any excessive reproduction of the worms provides more fish food. No waste!

Grow beds:

The 2013 expert opinions on the web prefer the grow bed with media and flood-drain water control using a Bell siphon to drain.. It is cheaper than mist systems and has better temperature control than the plastic pipe system. Raft systems are limited to certain plants to be grown. For the beginner, the IBC tank-grow bed is a good, cheap module to use while learning.

Media of gravel or non-calcium based rock is cheapest; baked clay is light but expensive. Small size increases surface area for beneficial bacteria growth.

If using a Bell Siphon, install it at the opposite end of the grow bed from entry of nutrient-rich fish water. When making a Bell Siphon, the distance of the bell top from discharge stand pipe is critical. Also, for more efficient siphon action, the top of the stand pipe should be level and with well sanded sharp edges. Also, a reduction from top of standpipe to the smaller stand pipe increases efficiency of starting the siphon. If properly made, a ‘snorkel tube’ is not necessary.

The top two inch layer of the media that is kept dry helps prevent weeds from growing, fungus or harmful bacteria from growing to harm plants, and saves worms from being drowned. Total media depth is: 2 inches at top that stays dry and 10 inches that is flooded and drained by the Bell Siphon. The plastic grow bed shell should extend 2 inches above the media bed with an overflow pipe to return water to the sump tank if stoppage occurs in return plumbing. Total grow bed height is 14”.

Filtered water on a larger system is held in a sump tank and pumped up to the grow beds (to avoid changing the fish tank water level). A pool pump is a proven, long lasting pump used by aquaponics growers.

A back-up electric system is a necessity to provide electricity for the water pump and air pump supplying oxygen for the fish. A cheap battery back-up and small solar panel can cut costs in sunny areas. Also, the battery back-up can be charged with a low-cost auto-battery trickle charger. Power outages are rare, but deathly to an aquaponics system.

For temperature control, a simple rocket stove is easily made with a few tin cans, and fueled with the lawn bush cuttings (free), scrap wood (free), or wood pellets (cheap) when heat is needed. Some fish require a warm temperature. Preppers or survivalist provide many ideas for heating air, food, or water.

Green house: Probably the easiest and cheapest greenhouse to build and easy to expand is the cattle panel, plastic covered greenhouse. A cattle panel four feet, four inches wide by 16 feet long is made of galvanized 4 gauge, steel wire and cost from $15-$25 each. To transport in a pick-up truck, panels are doubled end to end. The ends should e tied to avoid physical harm when unloading.

By placing three panels side-by-side, you have a 12-13 feet wide by 13 feet long greenhouse, sufficient for one IBC module and two grow beds. Width will vary according to height of stem wall around greenhouse (2.5’ to 4’ high) below the cattle panels. Add another panel and your 13 foot wide greenhouse is now 17 feet long, and etc. Easy expansion! NEVER FORGET, SMOOTH SIDE OUT; CATTLE PANELS AND TIE WIRES TO PRESERVE PLASTIC COVERING.

Plastic greenhouse covering varies in cost and quality. Top quality diffuses the light, eliminating shadows, and should last four years unless heavy winds are common in your area. Cheap quality plastic probably will have to be replaced within one year.

The stem wall allows a wider greenhouse by increasing head room. The stem wall improves ventilation of the greenhouse with more entries for incoming, outdoor, CO2 air for plants. Also, a stem wall eases insect and animal control, and improves insulation when cold weather arrives.

Again, there are many ideas on the web for you to adapt for you site.

This information is basic. You need to do a lot of research for information readily available from the web. Some good sources of information, at no cost are:

Video – The IBC of Aquaponics (Australian Faye Arcaro of Backyard Aquaponics demonstrates ease of converting an IBC to a fish tank and one grow bed) This video is used by everyone – probably the best guide. There are others, but this one is logical. (

Part 5 – Plumbing and Water – Heating and cooling:!

Part 7 –Changes to System and Discusses types of Systems:

Part 8 – Permits, Regulations, Fish Suppliers

Part 9 – System Cycling – Temperature Regulation – PH

Part 10 – System Cycling, Regulatory Woes, and Plant deficiencies

Part 11 – Approvals and Declines!

One grower’s use of cattle panels for the greenhouse. He designed his by raising the level mounting wood (2” x 6” and 2” x 4”) four concrete bocks high to increase the height of the green house (30’ x 12’) and easy ventilation for incoming air. Exhaust at top at far end. The whole structure cost $140.


pH of established, well cycled tanks needs to be tested every week or more often. A pH of around 6.2 – 6.4 is best, though this varies somewhat depending on the species of fish.

If pH gets too low, it could be a sign that parts of the media bed have developed anaerobic bacteria, which produce acids. If this happens, remove any plants with very large root systems, as these create pockets where air cannot access.

If the pH is too high, it is generally a sign that the system biofilters are not keeping up with the fish’s production of ammonia. Plant more plants.


Aquaponic systems require an air pump for the fish tank. Having the flow from the gravel beds falling from a height and splashing into the fish tank will help oxygenate it.

It is very important to keep the aerator pump running at all times. If the oxygen supply to the fish is cut off for just 45 minutes, you will have dead fish. For this reason, it is wise to have a backup air pump that will kick in if your pump fails. There can never be too much oxygen in the water; as excess oxygen will bubble to the surface and escape.


A lot of aquaponic systems require calcium, potassium and iron to be added about every two weeks. If you have a wormery add a little of the worm-compost to the water flowing into the gravel beds, this will provide some missing nutrients. Worms help more than just eating waste.

Which system? Backyard Aquaponics says:

“Through lots of experimenting over the years, and through the trials of members on the online discussion forum, the flood and drain media based system has been found to be the most reliable and the simplest method of aquaponics, especially for beginners. It can be done very simply using a wide range of different containers. The flood and drain media bed system also requires minimal maintenance.”

Fish Stocking:

“Fish Stocking: Every system is different and people’s environmental conditions can vary quite a lot, but there has to be a guideline as to what will work well for the majority of people. We recommend stocking around 20-25 fish for every 500 Liters of grow bed media in your system, this is assuming you have grow beds that are around 25-30 cm deep (10–12 inches)”.

So, let’s say perhaps that you are looking at making a very simple system like the example system we have built in this manual, made from the one IBC cut into two pieces to make the grow bed and fish tank. This grow bed has 250 Liters of media in it, perfect for around 10-12 fish. This is allowing for them to grow from fingerling up to a plate size of around 400-500 grams. If you double the grow bed by adding another one the same, then you can pretty much double the amount of fish you have to 20-25 fish in the system.”

We’re growing a variety of organic seeds in each of these categories.

  • Basil Green Peppers Swiss Chard Cucumbers
  • Romaine Lettuce Jalapeno Peppers Tomatoes
  • India Mustard Chinese Cabbage Long Green Beans
  • Zucchini Bib Lettuce Basil
  • Pak Choi, Bak Choy, or Joi Choi A & C Kale Eggplant
  • Leek Iceberg Lettuce Green Onion
  • Green Swiss Chard Hot Peppers Yellow Crookneck Squash





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