Backyard Aquaponics
A place to discuss aquaponics

EB and all,

Does anyone think it would be beneficial to have a thin layer of gravel and or organic matter in the bottom of the fish tank?

I'm just thinking the closer a system can be to nature the more in synergy it will be?

It would provide the oportunity for aquatic worms to breed, which can feed fish, yabbies, and water insects, all of which ultimatly contribute to the food chain.

The trick is not to have any anaerobic conditions and gravel can house anaerobic pockets quite easily. To this end undergravel filters with gravel wouldbe more suitable drawing oxygenated water through the gravel forcing the bad guys out.

A sloping pond with a good bottom drained UGF would be a great worm housing and definately benefit the system with increased decomposition and improved micronutrients, plus michorhizal fungi and other goodies associated with worms.

holding solids within the system does allow for the slower process of minerisation to take place adding still more nitrate to the system. normally you try to avoid this in plain aquaculture and remove all solids.
anerobic areas are scary they produce toxic gas and break down nitrate to steal its oxygen.
blodger

Yeah, I'm not a huge fan of gravel in the fish tank, could possibly cause problems with pumps too, I guess it depends on what you want from the system. If you are wanting to produce fair amounts of fish it's a lot easier when the fish tank is a clean environment, gravel will trap sedement and when the fish are disturbed they stir all of this sedement into the water...

This is how I keep the bottom clean on my big system, harrass the fish a bit (standing close to the tank) they then go to the base of the tank and aggitate any settled sediment, bringing it into suspension, the pump then pumps the sediment filled water into the growbeds.. It's been working fairly well for keeping the bottom of the tank clean so far.... Periodic fish scaring......

Make 'em work for ya

Nothing like scaring the bejesus outa your fish to clean a system... poor buggers