Nice project! Looks like a professionally made product. I've been wanting to try a HMF on a river tank build. Is that pieces of glass holding the sponge form in place I see (don't see much, if any silicone though)?
But does anyone foresee shrimps climbing up the sponge wall and out the tank being a problem?
I've heard of shrimp climbing out of tanks, but not sure if that is only due to water quality reasons. I suppose you could just trim down the sponge a bit if that is the case, though some shrimp might go on the other side of the sponge.