Anyone ever had zoos that shrunk?

[whalloper]

Hello all

I was wondering if anyone out there might know reasons that could make zoos shrink. The tank is 72 gal with 220W PC's. I am upgrading my lighting to 2x250W HQI w/ actinics this week.

There are only two types of zoos in this tank and everything else, mostly soft corals and lps, is doing fine. I dont typically feed my corals which some of you may not agree with, but my small 26gal zoo tank is thriving (with metal halides)... so I dont think thats it.

Please let me know if this has happened to anyone out there and if you know what to do, as I would like to frag many of my healthy zoos and transfer to the larger tank.

 

[ficklefins]

What do you mean by shrink? Did the size of the zoa itself shrink, or did the colony (# of polyps) get smaller?

 

[whalloper]

the zoos actually are smaller now than they used to be - like about half the size they were, but still open. Even the skirts are shorter now. Do you think it could be my current weak lighting?

 

[ecotoxlady]

Not necessarily a bad effect. As long as the zoas are open then I take that they're happy. For some reason zoas can shrink under different conditions (both lighting and flow) so unless you see the numbers of polyps start to dwindle, I wouldn't get too worried about it.

 

[whalloper]

ok, hopefully the new lights will make a difference - I guess what worried me is that they just dont look as healthy as they did overall. The tentacles on the skirts are very short and slightly uneven, and colors not as bright.

I used to religiously dose iodide which I think I will go back to doing.

what do you think of my water flow?

2 rio 800's (about 200gph each)
Sump return which is rated at 750gph, but in reality, probably more like 300gph by the time it gets back up the hose.

So I would estimate about 600-700gph on the 72gal tank