I have read that 300mm is the minimum depth for a grow bed. What is the maximum? I am thinking of cutting an IBC in half and using both halves as grow beds. That would make the grow bed 480mm depth. Of course I don't have to use all the space, but what if I did? Would there be any repercussions?
Also, sorta off topic, if I had a grow bed to tank ratio of 1:1 then wouldn't that empty out the tank? I supposed it would be offset by the grow media. So how much drop would I see? If I was doing a 2:1 or 3:1 GB:FT ratio then how much drop would I see in the tank? Would I need to cycle the 3 GBs on a timer?
Finally, would there be any draw backs to using an outdoor pond if it was designed so that a lid could be put over it? I am thinking of using one as my FT as pond liners are cheap and perhaps being in the ground would help stabilize temperature.