If you have absolutely no idea what aquaponics is, or why we’re talking about poop here; check out our Aquaponics System In Costa Rica. It’s a system that combines fish farming and growing plants without soil.
Poop is the lifeblood of any aquaponics system. The fish eat. The fish poop. Then, nitrifying bacteria convert the fish waste(ammonia) into usable nitrates that hydroponically growing plants can uptake. It’s a beautiful and fun way to hack nature to produce a steady supply of fish and veggies. However, in most aquaponic systems, 100% of the water is recirculated and the build up of solids can cause problems.
When we built our system, we thought our rock grow beds would handle all the solid waste just fine. After 6 months of wracking our brains and repeatedly cleaning out the grow-beds, we finally gave in and built 2 radial flow solids filters. Some leftover 55 gallon drums in the shed were the perfect size for the task.
The video below shows their build and function.
After in installing these radial flow solids filters into the system, our problems were solved. The amount of solids dumped into the grow beds dropped drastically. These filters were also a huge help since we have an outdoor system and the fish tanks are always catching debris from the windy days here in NW Guanacaste, Costa Rica. I highly suggest adding this type of filtration system in your initial design.
Here are 2 suggestions if you build a radial flow solids filter for your system.
1. Attach the settlement shroud to the lid of the drum. I’m seen a lot of designs with buckets, pvc, cable supports, and multiple other ways to suspend the shroud. Get a lid……bolt it on. It’s much easier. In addition, it keeps animals and debris out. For the shroud, you can use a cutoff white tank like we did, or a 5 gallon bucket will probably work too. (you can see how we did it in the video)
2. Don’t sweat all the designs on YouTube and Google. You can refer to the pic below, but it’s one of many ways to do it. Build it so that water is pushed up, goes into a chamber and is forced to settle on the bottom. If your outlets going to the grow-beds are skimming off the top, it will work. Have fun designing it!
Below is a picture of our finished radial flow solids filter. We ran the clean out valve up from the bottom and made a faucet so that we could fill a paint bucket with fish poo sludge. It makes GREAT fertilizer!