The accumulation of particulate wastes in an aquaponics system (which largely comprise faecal matter and uneaten feed) will negatively impact your fish in a variety of ways including:
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Solid wastes may clog bio-filters and reduce their operating effectiveness.
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Particulate matter consumes oxygen during decomposition which means that there is less oxygen for the fish.
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The presence of solid wastes encourages the growth of heterotrophic bacteria which (since they grow much faster than nitrifying bacteria) may compete with nitrifiers and inhibit their function.
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The breakdown of organic matter in the system will increase ammonia levels which can destabilise nitrification.
- Suspended solids may function as a refuge for pathogens while they look for a live host – your fish.
- Fish gills can be damaged by solids while breathing or feeding.
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Solid wastes will, over time, build up in pipework and fittings and limit water flow.
Not only should solids be removed, but the sooner they are removed in the process the better, because:
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Sedimentary solids will be churned up and become suspended solids.
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Suspended solids are more difficult to capture.
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Small particles leach larger amounts (relatively speaking) of ammonia and other unhelpful substances than larger particles.
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The longer that solids remain in the system, the more oxygen that will be consumed in their decomposition.
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The removal of finer particles involves greater expense since the biological treatment of solids invariably requires equipment and processes which are more expensive than mechanical filtration.
To summarise…….get the solids out of your aquaponics system - and the faster the better.
-o0o-
{ 3 comments… read them below or add one }
We could remove sedimentary solid by using a clarifier but how do I remove suspended solid? Does letting the water go through the duckweed tank helps capture the suspended solid or should I let them pass through a bulk of fine netting? I quite confused with this issue of suspended solid and hope you could advice me further…
Arthoz…….suspended solids can be removed by using mechanical filters. These include (at the expensive end) bubble bead filters, Nexus (or similar) filters or fluidised bed sand filters.
At the less expensive end of the spectrum, we have mineralisation tanks which contain nylon bird netting or manufactured plastic media or filter (Matala) pads.
In a large aquaponics system, the suspended solids can be left on the media where they will mineralise. Periodic cleaning is useful to rid the system of any accumulated sludge.
In small systems, regular cleaning is required so ease of maintenance is the key to successful removal of suspended solids.
In this we agree Gary. but how does one design for solids filtration in their system?