Solids removal is an important part of any aquaponic system, especially systems like raft systems. In a raft system, you have to use some type of filtration to remove solids, or your raft beds will accumulate waste, your dissolved oxygen will crash, and your plant roots will not stay healthy. Media based techniques on the other hand, use the media bed as a sort of filter to remove solids. ZipGrow towers, for example, act as mechanical filtration; the solids are sent into the tops of our towers and catch in the media, where they are broken down by redworms and bacteria. By the time the water drains from the bottom of the tower and into the gutter, it is clear and clean.
Media-based aquaponics systems
If you’re already using a media based system, then solids probably won’t be an issue for you. If problems with solids do arise, it's likely that your stocking densities are too high or your medium is too fine. If your stocking densities are too high, you’re 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. When this happens, the waste decays rather than being broken down quickly. Decay consumes oxygen, so decaying matter will cause your water to be anaerobic. This is one reason why it’s important to use larger media sizes (not pea gravel or sand!). Our media is not dense (93% void space), so it allows water to travel freely through the material, even when there are lots of solids present.
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 aquaponic filtration
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