Backyard Aquaponics
A place to discuss aquaponics

Hi all! .... (I hope you like the long post's)

First of all, i want to thank everyone for all the information and help that you provide through this forums, i think Backyard its one of the best AP sites on the web, and thats why i'm here

I been reading about aquaponics about 2 years ago, from the beginning i though that it was almost magic, and become very interested. I read a lot of information trough this time, so many forums and pdf's!.. I think i'm almost ready, so the time to take everything to practice as become!

Like the tittle say, the concept of my system its make it as simple as possible (And cheaper). In the future i will try to provide this system to the poor people around here, so it will be nice to have an easy aquaponics to reduce costs, reduce points of failure and make the maintenance easier for the final user.

Im going to start with a small system (About 400lt), to try the concept; but the final option will be above 1000lt. I choose the Deep Water Culture option because its a little bit simpler and probably cheaper.

I'm about to start the building, so any suggestion will be very welcome!.

The material choose was easy, wood, its very low cost in my region. All the structure is made with wood, treated to make it water resistant. Once i have the main structure, i will add some sheets of MDF 3mm to the surface of the tank. The MDF will be cover with 1mm sheet of Polyethylene plastic to contain the water in place. Total cost of this is about 60 USD.

Some renders and notes:









Like you see in the image, its pretty easy to build, just some wood structure and plastic on it, the total volume its about 420lt. I put a larger bomb because i add a venturi aeration and i need a rapid movement of the water (2 or 3 cycles per hour). I have this theory... i think i can reduce the rot roots if a have a strong water circulation in the Grow Bed, so i put the out pipe of the bomb in my GB with some nice venturi aeration, providing fast water and a lot of bubbles (and O2) to keep the plants and bacteria happy. The usual rafts of polystyrene will be on top, and i will add some hydroton or bioballs in the botton of the GB to have more surface for the bacteria to grow /Maybe about 1 or two inches of balls, cover with mosquito net to avoid the movement).





THe main aeration system will be the venturi 1 (Grow Bed).... but in order to mantain my fish living, i put the grow bed 1.2mt above the ground, so i can have a good pressure in the exit pipe of the GB just with the help of the gravity. At the end of the exit pipe, i will put another venturi system, more simpler to add some oxygen to the fish. I hope that with the venturi 1 and venturi 2 i can have enough Dissolved Oxygen for the all the living things in that boxes. Like i said, im triying to keep it very, very simple. Just 1 bomb to provide water and oxygen for all. I need to make it work.










The venturi systems are copied from some diagrams (from here and other places), those are the first drafts, but i attempt to make a lot of tests to obtain the best oxigenation from them.

Finally, we all know that a DWC need a good filter to keep the plants OK, so i have this idea:








I will place a tube filter before the intake of the pump, inside the fish tank. A mechanical and biological filter inside the fish tank...... with this, and the fast circulation of water, i hope to avoid the clogs of solid waste in the roots.

The filter, is made of a PVC tube of 4". Its easy to remove because it will made of 3 parts, the conection with the bomb, the heavy filter, and the biofilter. The first part, the biofilter, its the entrance of the water. This 50 or 60cm or tube will be filled with hydroton or bioballs to have filtration of large solids and to keep some bacteria living in this area. Its sealed with mosquito net to keep the balls in, but i can remove the cap to let the balls out and remove the acumlation of solids (Inside the tank to mantain the bacteria).

The second part, is the heavy filter. First some net's to retain the rest of the solids, and after a couple of sponges to filter the small particles. Thats why i have a larger bomb, i need it to have enough force to create a good negative pressure and move the water through the filter, and to the Grow Bed with good pressure and flow.

I think, that all of this its very experimental, but its the purpose of this prototype, i read a lot about AP but with all that information i can become a little confused and probably have some big errors in the design, so i hope you guys can help me, guide me and hopefully give me some advices to start building this in a couple of days.

So.. it will work???

I foresee lots of issues here!

I don't believe you'll have enough biofiltration in your simple cannister filter, and in any case you're going to be blasting water through in high flow, high pressure so all you're going to do is blast clean the media and blow holes through the fine filter mesh, or in the least you'll have high back-pressure on the pump which is exceptionally inefficient! If you don't have the space to install a separate mechanical and biofiltration sub-system, look at some of the in-aquarium designs utilising high SSA media such as kaldness etc. Instead of having the filter pressurised, I'd look to position the filter(s) above the DWC and let the water fall utilising gravity into the DWC.

Instead of blasting water through the roots in the DWC, I think you'll have better results by pre-filtering the water and moving the water sedately through the roots, and using supplemental air if required.

I'm not a big believer in adding constrictions to drains, and I don't think that adding a venturi to the drain from the DWC to the FT is going to add any more air than simply dropping the water from a height into the FT, or using some other designs in the drain to "suck" in air and deliver this to the bottom of the FT (I've used these with very good results, I had some videos somewhere on this forum if you're really interested?)

I think you create a workable, cheap, efficient system using a small water pump to lift the required volume of water to the max head, gravity feed through a mechanical filter(s) into the DWC, gravity drain into the FT, with an in FT biofilter fed by the drain (or the biofilter can be positioned between the mechanical filter and the DWC).

Hello Bunson, thanks for the advice's!

You are right, the tube filter probably wouldn't be enought...and it will make it harder to the pump to work (Consuming more energy and making the system more expensive).

I'm currently making some changes in the design to put the Filter above everything like you said, i think i will choose a hybrid radial filter with some media in it to add bacteria and filtration... it should work.... i just will miss the pressure. With this new layout i wont be able to use the "T" venturi system, and will be necesary to add some air pump to the system (What i tried to avoid).... i will think more about this and try to keep the air pump out of the equation (Some ideas?).



I think the venturi 2 its kind of what you said there... (Or maybe its not a venturi, just a tube sucking air?).... but i hope you can put me a couple of links to check a couple of better options.

So i will update this threat later with the mod's, but i really hope i can get rid of the airpumps and keep the system simple and cheap.

(Sorry for the bad grammar and weird english, im not too god at it! ......Greetings!!

Video of two different configurations of drains from GB directly into FT, carrying air without venturis.





I posted some of the designs on my system thread : http://www.backyardaquaponics.com/forum/viewtopic.php?f=18&t=5950&p=339240&#p339235

If you keep the stock density to a "reasonable" level, the water dropping into the FT will provide more than adequate aeration for the fish and the DWC; you should still have a backup air or water pump.

I know you're trying to keep things simple, but I think you'll actually end up complicating the processes if you attempt to combine different filters into a composite unit; I reckon you'll get better results and a reduced maintenance routine if you have a RFF feeding a mechanical filter feeding the biofilter feeding into the DWC. If you have the space, a larger RFF may remove the need to have a mechanical filter and you could feed the biofilter directly from the RFF.

Bunson i just read your history with AP from the beginning of your experiments, its was fun, and little sad overtimes...(Electrocuted fish, some constipation, sepsis.... and when the first system was abandoned )... But overall was very informative!.

I cant wait to start building this!... but first i need to fix all the troubles with the design.

Fist of all, i move the filter and take out the venturis, im not planning to have a lot of fishes like you said.... so probably this will be enough. Of course i will have a replacement pump and some UPS energy backup in case of electrical shortages. The aeration system its very simillar to yours.. the videos show some nice bubbles, but i add an air entrance at the top (It should help right?). If i dont get enough O2, im planning in divide the outlet of the pump, 80% to the DWC and Filter, and 20% trough a venturi in the fish tank.





About the filter, yeah i recognice that if i make an hybrid system maybe it will get to complicate to build or mantain, i just spend several hours searching about this topic, to get to these conclussions:

- DWC definitely needs good filtration (If we like a fast growing in plants).
- Radial filters are the best's
- A radial filter works slowing the water and changing the direction of the flow, in the first step the water goes upside, then down to the base of the filter, where it goues up again. Its desirable in this step, to have a good velocity in the water going down (To push the solids at the base)... and a very slow movement to the top (To let the solids behind)....

I think i can put some biolfilter with light media, like bioballs or kaldness in the last step of the filter, where you want to have a slow water and its solid "free". The biomedia will be floating with the help of some mesh, so we have the botton of the tank free, to colect the solids.





Well i think in theory should work, but what you think about this?, its a good idea or i should stay with the basic radial with no modifications?


Keep in mind that i want to make an eficcient, simple and cheap system... probably not possible .. the system its designed to probably feed a whole family with low resources, so it need to be simple, just 2 tanks in ground, one pump... and thats all!.... Their houses much of the times dont have electrical power, so im triying to make it work with just one pump to have low power consumption (And feed all with some solar or wind energy).

Thats why im triying to get rid of air pumps (More points of failre, more devices... i hope the pump can do everything!... from move water to a proper aeration).