Quote:
Originally Posted by tsicar  just a comment on the whirlpool: if the tank is circular and you have a circular motion of the water (whirlpool), the worst of the solids seem to congregate at the centre of the tank, so perhaps this should be where the syphon is positioned? |
This is correct, it's just that the diagram is simplified. The hose filling the tank also needs to enter at an angle rather than just dropping in.
The growbed is actually the biofilter filled with gravel. It operates on a flood and drain with a loop auto syphon (shown as B on the diagram). As a rule of thumb, the grow beds should be twice the size of the fish tank, so you can imagine just how much vegies can be produced. The only thing that needs to be added is chelated iron and maybe seaweed extract for micronutrients.
Worms can be added to grow beds also, however in my system I found they somehow appeared by themselves. Growers have reported that after more than a year of production, their growbeds remained clear of dirt and dead plant roots - thw worms ate everything.
The part at the bottom is a sump, the level fluctuates with the flood and drain cycle of the growbed. It must contain enough water to fill the the growbed and have the auto syphon kick in. Otherwise the sump will run dry and this system stops working.
Not sure if I've explained it clearly, if not let me know.