Zoo's won't grow

[Clownguy]

I have an sps dominated tank and wanted to get something colorful and something that moves a little bit so I tried some zoos. Well, to make a long short I have had some neon orange zoo for about 5 months now and they have barely grown and have not really spread like they use to when I had a tank with VHO only. My setup is a 150 pentagon with 3 PFO 250 HQI MH(2 20K and 1 10K) with 4-24" VHO bulbs actinic. Flow is done with a sequence hamerhead(5400 GPH) run through 7 outlets(2 3/4" Seaswirls, 4 3/4" bulkheads and 1 spraybar) as a closed loop, and my main pump runs at 1500 GPH. THere is lots of flow. Currently they are placed about 2/3 of the way to the bottom and have started to turn brown and have lost most of their color. Water parameters: NO3=0, Phosphate=0, pH=8.2-8.4, Ca=420, Alk=7.9, salinity= 1.024. I don't know what's wrong help please.

Chris

 

[sryder]

it may just be the type of zzos. I have some oranges that also are slow growing. I also have some other zoos that spread pretty quickly.

 

[mfinn]

Some zoanthids are just very slow growing and some don't like the really intense mh light. If you can move them to a little more shaded spot.
The ones that have already turned brown won't change back but new growth may come in orange.

 

[shallowreef]

Whats a ggod way to tell if zoas should be placed close to or far away from the lights? Are there any tell tale signs?

 

[mfinn]

I haven't found a foolproof method. I always start them low as possible and work them up a little at a time. I haven't found many that like full, up close mh.
I do know the really electric blues will fade badly with direct full mh lighting.
Some like the ppe's I keep shaded all the time.

 

[Clownguy]

For me this was a wierd situation because the person I got them from had them under halides of the same intensity, but I guess they could have been a little more out of the light. I will try to move them down in the tank a little. Thanks,
Chirs

 

[MarineTeng]

if they're too far away they stretch out their necks and are kinda long, and i think i've heard that too much light would make them shrink back or something