Aquaponics Use Of Tank Water For Plants

I was with a group of friend's last night and we were talking about our gardens and our pets, and the subject of aquaponics came up. I was curious as I didn't even know about this practice of raising or growing fish in a type of recirculation system.

The fish consume food and excrete waste, that produces a nutrient-rich solution in the water in which plants thrive on.

The plants take in the nutrients through their roots and at the same time the plants help to purify the very water in which the fish live and return the clean water to the fish tank.

Somehow the tanks are set up in such a fashion to allow the water at one end to be pumped from the fish tank, where it enters a growing and floating bed. Gravity pulls the waste through a gravel bed, feeding the bacteria, which in turn feeds the plants. The clean water is then returned to the fish tank.

The only time I was aware of plants that help purify water was in Florida, where the Water Hyacinth (Eichhornia crassipes), serves that same purpose in the canels and waterways, while it takes over the span
of the entire canel or old river channel.

Does anyone here know about this system of recycling fish tank water in such a fashion that both plants and fish benifit?

There is no true self-sufficient aquarium system.
If you understand aquarium nitrogen cycle, you should know fish produce ammonia. Ammonia is toxic to the fish, it must remain at 0ppm concentration in the aquarium water or the fish will eventually die. In well established aquariums, filter systems can develop colonies of specific bacteria species to feed on ammonia. They turn ammonia to nitrite, before turning nitrite to nitrate. Although nitrate is relatively safe, too high concentration of nitrate is still bad for fish. Now there is no true way to get rid of nitrate from a closed system such as in an aquarium. It is why we often do weekly partial water change. The main purpose is to get rid of nitrate.

It is true aquatic plants can absorb a small amount of ammonia and nitrate. The quantity is too insignificant to be enough. You will need to have plants covering every square inch of a 30 gallon tank just to be able to take care of the ammonia produced by a single 1.5" Neon Tetra.

I have been running planted aquariums for years and I know how quickly nitrate can build up even in heavily planted fish tanks. Unless we are talking about just one tiny 2" fish in a 55 gallon heavily planted tank, you will still need an aquarium filter system to convert ammonia to nitrite or there will be ammonia spike. You will still need partial water change on weekly basis to keep nitrate down.

Now what you talked about is similar to a sump. It is usually a secondary tank hanging behind the main show tank, where you can add additional filtration to it without making your show tank look bad. Certainly you can plant tons of plants in the sump if you wish, but it won't be able to take care of the ammonia produce by the fish unless we are talking about a 5,000 gallon sump for a 50 gallon show tank.
The function of a sump is usually to hid your filtration system from the show tank, and of course it will allow you the option to have more filtration than just have a normal tank without sump. It will help the water quality for sure but not to the point where you do not need to do partial water change.

You also need to understand that nitrate is not the only organic waste ended up in the aquarium. There are also phosphate and other stuff produced from rotting fish waste. Without partial water change once in a while, the fish will be literally swimming in their own waste. It is unhealthy for them.

Ram,
Thank you for all your knowledge and wisdom. As I said my friends were discussing this idea, having read it in a magazine somewheres and were wondering if it could truely work as it seemed kind of far fetched. One friend of mine raises just plants that way in his green house. It is quite a set up of tubing pipes of different sizes and floating bed trays. It is interesting to hear him talk about the set up.

So do you have just fresh water tanks or a salt water fish tanks? I know the salt water ones can be a little harder to maintain.

We had a small fish tank when I was a child, a very long while ago, with a few guppies and angel fish. In Florida, we had outdoor pools and tanks and a large lake, filled with fish and alligators.

This project is definitely not for the faint of heart. I've read articles on it several times and it takes up a lot of time and resources at the beginning. You go through a lot of trial and error as you try to balance your fish species with the plant life you have chosen. There are also a lot of details and tests you need to perform to ensure the health of your growing population.

trishgl,
if you want more information on this subject check out my other post in this section called, Aquaculture Bioshelters for Raising Fish. It includes the plans on how to raise plants and fish together under the same roof or in specially made tanks.

Thanks for sharing your opinions here.

Nitrate, the end product of an aquarium filtration system is also a main source of nutrients for many plants, even your good old garden plants and vegetables.
I am sure that the system could be made pretty much self sufficient but from a hobbyist point of view it would take some setting up to make the whole thing aesthetically pleasing. For experimental purposes though one could be set up in a car-less garage or large shed.

Aquaponics has actually been proven to be not only feasible, there are companies that specialize in setting up aquaponics systems for farmers.
Basically the systems involves pumping aquarium water with all the fish waste through a biofilter where the bacteria can metabolize the ammonia into nitrates which can then be used by the plans in the growth beds.
I believe the set-up needs some time to stabilize and to let the nitrogen-fixing bacteria to fully develop.

I have seen articles about this as well, and if it is set up properly, then it seems to be a viable way to raise your own fish for food, as well as grow your own vegetables, and each one helps the other to be healthy and grow better.
I have also read about a man that raised catfish in a 55 gallon barrel. He did not filter it onto a hydroponic garden, but he did reuse the water into his vegetable garden through a regular hose.
Then he also grew earthworms with the compost from the garden, and fed the works to the catfish, so it all worked together for him ,too.
He had to drain water from the bottom of the Barrell every day or so, and refill it with fresh water so the fish could breathe.

Aquaponics can be used to cleanse the water of an aquaruim. The basics of the system are similar to the system used by the large water companies in sewage treatment plants before the treated water is then filtered. Theoretically you could use it for a normal home aquarium but the system would require a lot of space to set up. On top of this, partial water changes would still be required to reduce any nitrate not consumed by the plants. If you have a large interest in this type of system and have the garage space to set it up, required tanks, lighting etc. if would be a good experiment to monitor.

That's the thing, what would be the best plant-to-fish ratio for an aquaponics system to function properly without having to have partial water changes from time to time?

Also, what would be the best species of plants for a tropical climate? I've heard people even growing things like tomatoes and lettuce with this system and this is very interesting for me as I have been asked to work with an NGO in South East Asia and using this technology would be a great addition to our renewable-enegy and renewable-resources project.

I did a lot of research on Aquaponics and decided against it for my family as we simply do not eat enough fish to make it a viable solution for our food needs. However, I have a friend who successfully had two tanks going in her Michigan basement (she just moved to South Dakota) and her successes are what turned me on to the idea in the first place. Her family exclusively used tilapia in their tank, and grew a variety of herbs and vegetables.

Primarily she grew lettuces, tomatoes and basils. Plants that require an acid environment won’t do that well as most aquaponic systems thrive with a more neutral PH of 4.0 – 5.0. My friend invested in a variety of books and guides, but after setting up her tanks the investment cost was around $1000. However, they found that over time it was working very cost effectively in feeding her family.

I’ll be interested to hear from her in how the tanks are doing in South Dakota. They rented a trailer and drove them there, so the transition in climates and temperature control should be interesting.

From what I have read about aquaponics, it can be adapted to about whatever size you want it to be.  There are plans online for ones that can be used in the house, to much larger ones that come with their own green house; depending on what your climate is like, and whether you want to grow produce year around, or just in the normal growing season.
With the price of meat going up more and more every day, if people do not make some modification in their eating habits, they will be spending most of their paycheck just to keep food in the house.
We have not normally eaten that kind of quantity of fish either, but many cultures who live near the ocean have depended on fish for their meat for many, many years.
Not only that, but if a person has a nice-sized back yard, they could also turn this into a great little home-based business ! !
Here is one video that does a good job of explaining how aquaponics works, and how to set one up.

You can grow just about any kind of plant such as lettuce. Kale are the easiest to cultivate and the fish container can be made out of fiberglass, glass, concrete, etc. Tilapia are commonly raised fish in aquaponics systems. You can choose the right one for your set up based on the way they look or the way they behave. Your main role is too feed them and maintains the water temperature and they would eat plenty of blue, green algae but The best option for your system is to locate an organic Tilapia Food.