Solids removal is an important part of any aquaponic system.
In raft systems this becomes expensive- you have to use some type of filtration to remove solids so that your raft beds don’t accumulate waste, your DO doesn’t crash, and your plant roots stay healthy.
Media based techniques on the other hand, use the media bed to remove solids.
Media-Based Aquaponics Systems
If you’re already using a media based system, then solids probably won’t be an issue for you, unless your stocking densities are too high, or your medium is too fine.
If your stocking densities are too high, you’ll be producing more waste than your media bed can break down.
If the medium itself is too fine, then the waste can impede the flow of water through your bed, clogging things up and causing the water to go anerobic.
This happens because the decaying waste consumes all of the dissolved oxygen. This is one reason why it’s important to use larger media sizes (not pea gravel or sand!).
Our medium is rather coarse (93% void space), so it allows water to travel freely through the material, even when there are lots of solids present.
Read more on Biological Surface Area in Aquaponics Here.
Raft Systems in Aquaponics
If you have a raft system, then you’d better invest in solids removal equipment. This reduces the overall nutrition in your system, but if you have proper mineralization tanks you can still maintain relatively high nutrient levels.
The Cost of Filtration
Solids filtration can be expensive- it’s one reason why we really like to use our trusty ZipGrows.
There are lots of great resources out there on how to build your own equipment so that you can save some money.
There are lots of great techniques- you’ll just have to do your research!