I've read about the square posts,
I've also read aboout problems from round tube(never experianced it though)
That Mom has roots into the reservoir and a mat all along the bottom up to the drain..
I run it about 3/4 to 1/2 inch deep.Just have to turn up the psi a little when the untill roots reach the bottom in my experiance

Glad to have your stink of approval

Mspb