Losing zoo's?

[MikeP]

I have this piece of LR that was completely covered in zoo's (not sure which type, they look like little brown flowers). Anyway they seem to be slowly dissapearing in one area. Everything else in the tank is doing fine. I have not seen any zoo eating hitchhikers so I don't think they are being eaten. Could they be to close to the lights? Or it there a zoo supplement I should be adding. I use kent marine phytomax a couple times a week.

Thanks for any info