Zoo Recession??

[vissichellimg]

I have had 4 seperate colonies of zoo polyps in my tank for nearly a year now. They used to look alive and vibrant Then would fade off for a bit and then would come back. In the last 6 months i have noticed them slowly receeding. What was once 20 big fat happy polyps is now 5 or 10 Shrinking not so happy looking polyps. Some open, others are just closed up buds that still appear to be alive for months now but they will not open up or spread.

Water parameters are all good, i tried frequent water changes, moved locations and no luck. I have a 29 gallon tank with 180 Watts of Power compacts, any suggestions or ideas?

Thanks

 

[kawicivic]

do you see white spots on the closed polyps?

 

[650-IS350]

pinching, algae growing on em', pox ???