slow - zero coral growth

[saltyrockbox]

I have had my tank for a year now and have a variety of corals softies, LPS, and one sps frag. All survive but they have not really grown at all, some tiny growth but really very very little in all. SOmtimes one will grow a bit and then stop. Even hardy corals like GSP seem to be slowly looking less healthy. (over the months)

My water chemistry seems great, but maybe not the most stable, I have moved from one big water change a month to weekly 10% changes, I have more crabs and now have zero algae in the display but I do have sheets of nasty algae in the overflow. I have a new ballest and more light power (4 over driven T5s covering every inch of the top).

It could be...a low flow problem, an unmeasurable nutrient problem, a toxin released buy the overflow algae (slimy algae) or the lack of perfect stability in water chemistry.

So I might have answered my own question but I'm posting because maybe someone knows something I might never think of...

Any Ideas??