Quote Originally Posted by davidstcldfl

Is there a problem with the fish and/or system ? or your just concerned because it doesn't look like much flow into the FT ?
Are you concerned with the DO ? Do you have a spray bar on the water going to the FT ?

Lots to consider...
David, thanks for your quick response. I am running an air pump for my fish tank. I am not sure if I can call it a problem, is more like a concern, but it could be later on: two out of the three growbeds are filling up and draining within 16 minutes which I understand is good I think. My third growbed is filling up and draining in 35 minutes, and I did that in purpose in order to get water back to the fish tank, if I adjust my third growbed to fill and drain within 16 minutes then I get no water going back to the fish tank at all. My question is : is it good or bad to fill my third growbed in 35 minutes or is that harmful in some way?