Very cool idea Wright! My only question is, how long can this system run before the algae growth chokes out the effectiveness of the UGF? I mean there has to be a point where there is too much algae for the water to flow properly. Ty Amen to that. Let me share a little under-gravel filter (UGF) trick that I learned from my Betta friend Lew Heifner. <snip>