Backyard Aquaponics
A place to discuss aquaponics

It takes a sh1t-locker of pumping pressure to force water through sand! If you ever switch the pump off, after the sand has settled, you may never get the water through the sand again with an aquarium/water feature sized pump, you'll need something much bigger; bigger means more $$$ to buy and run. High pressure pumps with relatively low flow are hard to find, spare parts even harder to find.

How do you intend cleaning this filter? Even with moderate stock density, I am going to guess you're going to need to take the thing a part about once per week? I reckon it would take about two hours each time to remove the filter from the system, unpack it, clean it, repack, re-plumb and restart. That's a lot of work, and every time you remove and re-plumb, you are creating unnecessary risk to cause leaks.


There are some simple rules of thumb that will help prevent you exceeding the right number of fish measured against your feeding regime and filtration capacity of your system; then halve it for newbies with new systems and increase the stock density over time, as the system matures and your experience grows.


The first-stage filter I'd use is a radial flow filter; I found this to be more efficient than a swirl filter (and easier to build from scrap). Paul from EarthanGroup has a good video on RFFs : http://www.earthangroup.com.au/radial-flow-filter-video/

The second-stage is a fines filter, easily constructed from a bucket full of (new, clean, non-soaped) scouring pads. Make sure to add an overflow so that should the pads become clogged, you don't empty your system of water.

The third stage is a biofilter, again Paul has some good videos : http://www.earthangroup.com.au/diy-5-minute-kaldnes-bio-filter-for-your-fish-video/

There's also heaps of videos of filters/filtration systems on YouTube, a brief search will have you wasting many hours watching what others have done. (It's just a personal preference, but I'd be looking for what Koi-keepers have done, as they are (generally) very precious about water clarity, so build some kick-a55 filters)


The best implementation of GB -> NFT -> FT in an IBC system I have seen was to position a "ring" of NFT channel (100mm DWV) around the top of the FT. The GB is supported higher than "normal", but still sits atop the FT, but instead of draining down directly into the FT, the GB drains into the NFT pipework which then drains through many, many smaller holes (25mm DWV) into the FT, with a "safety"overflow back into the FT. In the NFT, he grew strawberries which cascaded down the sides of the FT in summer and looked quite spectacular and provided some shade to the FT.


Have a look in the IBC of Aquaponics for more ideas, the link is at the very top of the page.


What's wrong with having the pump in the FT? A lot of people use this in very successful systems.

You and several other people have completely boosted my learning curve. I can see how I jumped in with assumptions and on the narrow stubborn side. I have a a Little Giant pump, not sure of its gpm or how high (nomenclature?) it pushes water, but it will splash the ceiling in an 8' room. Learned that by accident. lol Was suggested to look at http://www.matalausa.com/ and thought they looked nice. Will check the link you provided. As for my incessant desire for the slo, pump and bell siphon being external is just a preference. I think it looks cleaner and utilitarian. Its been made obvious that my approach is over thought. All the advice is very welcome, thank you.

what part of Texas are you in? I am in the Stevenville area. Jerry

East side of Greenville

Those are some serious filters! I've seen tons of simple ibc systems that only use the gb to filter. The purpose of the filter Im working on is to grind up the solids before it enters the bed. I will have to test the pump in the sand and see how much can be used so it doesnt pack up. The guy in the link looks as if he's about to outfit an Arcology structure. Im really not trying to buy a lot of things, all scavenge. The operation of what your suggesting is very effective and the output is surely straight h20 and nitrates. If its all that nesessary to biofilter like that, then my little "biofilter tower" isnt a big deal. Im going to go forward with my plan. A gallon of sharp sand for starts, if possible maybe a couple of gallons of the media you posted on top of the sand. Then ac fiter batting inside the 5gal bucket, and lava rocks in the outermost chamber. Will most likely use lava rock for a big % of the gb with hydroton on top of it. Thinking 4-5 inches of hydroton the rest lava. Most of my friends are saying k.i.s.s. rule and a few aim to high like a nasa mars settlement. Cant wait to just get it filled with water and cycling, because i have a wolffia tank to start. Going to have to grow my own fish food or they will have to learn to eat dog food or die. Theres a lake full of fish to abduct and experiment with.

Any sand filter will be extremely efficient at trapping almost all solids...

But unless you can oxygenate it... and backflush/empty it... it will just become an anaerobic putrid sludge...

Have to rethink some more. Seems that electricity is critical. Expecially is its cut off. Off the grid is the only secure way of doing this.