slow - zero coral growth

[Der_Iron_Chef]

I think it's always a shot in the dark, when you're hazarding a guess as to why two different tanks with seemingly similar statistics, experience such different growth rates.

My tank has never been really stable, for example. I don't have an auto top-off, and my water changes were sporadically regular. I dosed for Ca & dKH, except when I didn't...etc, etc. But I experienced some pretty crazy growth in some corals (some of those SPS). Others, like my purple mushrooms, which by all accounts should be spreading like wildfire, split at a snail's pace.

Having said that....what is your bioload like? Livestock? Do you test regularly?