Can't figure it out...

[a&m aggie 04']

I havent been around lately but I'm about to graduate and move back home. My tanks been here the last 3 years and i really havent given it the attention it needs. Every time i come home i have what looks like diatoms on my rock (it covers the corraline). So i simply take a tooth brush and scrub it off. Im thinking its there due to lack of circulation so i think i've fixed that problem.
What im really concerned about is corals slowly dissappearing. Ive had lots of zoo's and lots of mushrooms dissappear. Its not that they look dead one day. The zoo's would deplete by a few each day. Here's what i have in my tank.
Percula Clown
Cleaner Shrimp
Fire Shrimp
Blue leg hermits
Turbo Snails
Cerith Snails
Mandarin
Foxface
Other corals in my tank are doing great, numberous brains, frogspawn, hammer coral...
I dont believe to have any sundial snails in my tank, ive looked all over. What else could be the problem??

 

[dburr]

Is your tank fed every day? Maybe someone is snacking.
Or, could be some water changes will do some good.
Good luck with it.

 

[thomas712]

Lighting or preditors are two possiblilities, as well as water quality.
Zoo's dissapearing? Look for small starfish that could be covering them. Softies dissapearing? look for a small white slug that may be on them.
Improper lighting could make them waste away.
Thomas

 

[a&m aggie 04']

yeah the tank is fed everyday.
Lighting could be the issue b/c i cant remember if it was before or after i changed my bulbs out. But im running 4 36" VHOs over a 58, so im sure that's enough.
I'll look out for the mentioned creatures and will test out with some cheap mushrooms.
Thanks, Mark