Question for all "Zoo" people

[Biggen]

Hey guys.

Question concerning my Zoo's that I have. I have had one colony of green Zoo's for approximately 3 months now. However, over the last month they have started turning brown. The brown coloring appears right inside the oral disk of each polyp. I know that Zoo's really can't have too much water flow, but how about light? All my research leads me to believe they love high light situations, but I wonder. Mine are about 10 inches directly under my 250W MH bulb. I was thinking of moving them to the bottom of the tank perhaps a little directly out of the MH light. Do you think this move could be worth the effort, or just wasting my time? The Zoo's have attached them selve to the rock, however. This is actually a problem as the rock is too large to move to the bottom of the tank. My only choice would be to remove the Zoo's from the rock. Not something I really want to do.

Water params are fine:
pH - ~8.4 during day, ~8.3 during night
Ammonia - 0
Nitrite - 0
Nitrate - < 5.0 (not detectable with kit)
Ca - 330 (a little low but I have been having some problems raising this)
Alk - 7DKH (Same as above. Tough sucker to get up to my usual 9DKH)
Mg - 1250 - 1300

I have recently started feeding them more to see if I could elicit a change through this. Nothing has happened as of yet, however, I only started feeding them more sine Monday so I didn't except anything to happen this early.

BTW, I have read the coral coloration FAQ written by Eric Borneman:
http://www.reefcentral.com/forums/sh...hreadid=234253

The information is a little disheartening as he basically states that if a coral is changing colors, it is normally caused by the differences in lighting and nutrients from the habitat it was last located in. I hope this doesn't mean that I am doomed to brown Zoo's forever.

Good news is that my Ricordea should be in by 10:30 am. I can't wait!!

I know this contradicts most types of fluorescing corals but I find with zoanthuds, they do better when placed lower in the tank. They seem to respond well to intense lighting conditions but not as close as you have indicated. Also look at how the polyps themselves are extending. Generally speaking, when the zoo is "hugging" tight to the rock they are getting plenty of light (or in this case too much). If they are extending outward away from the rock and towards the light, they will not be getting enough intensity.

All the zoanthuds in my tank are about midway using PC lights and that seems to be where they do best. In comparison to the intensity of MH, I think you would have better results with midway or lower

Cheers
Steve

[Biggen]

Thanks for the response Steve. I am thinking they may be too close to the top so I may go ahead and move them down.

[reefrunner69]

Have you recently changed bulbs? What is the spectrum of your MH? I agree, they would do better on the bottom, but since changing my MH bulb, I am experiencing problems with my zoos, changing colors, so it's a possibility.

[Biggen]

Have you recently changed bulbs? What is the spectrum of your MH?

I haven't changed it since I put it in in October. I haven't had the Zoos that long so they have been under the same bulb the whole time. Its a 250w 20,000 K Hamilton bulb.

I moved them to the bottom of the tank on a rock. We will see if this works or not. I am also going to be adding an 03 PC to my light setup. I am only going to use a single 65w PC lamp. I really want the added "blue look" and it will should also help the coral really "light up" and will hopefully improve their condition as well. Can't wait to see my new Ricordea under it.

[reefrunner69]

Can't wait to see my new Ricordea under it.

Dude...we can't wait to see them period.......post some pics already

[Biggen]

Dude...we can't wait to see them period.......post some pics already

When I go into feed tomorrow morning, I'll snap some picks as the light turns on (Super blue, almost 03 looking when the lamp first turns on). It will be their first experience with the light, but they should be open most of the way. When I left this evening, they were all open and doing fine (with the light off of course).

[loganj]

I have the same zoos in a 20 gal tank at three different levels under PC lights. The ones closest to the light are more brown and are hugging the rock tighter. The ones on the substrate are more green with a slight brownish tinge on the edges and stand up 3/4" off the rock. I think moving them away from the light will probably fix the color in time. JMHO.

[Biggen]

I think moving them away from the light will probably fix the color in time. JMHO.

This is why I joined this site so long ago (at least it seems long ago)!! Thanks for the help with these guys. I really want to get them looking green again. I didn't think to place them in the sand. I guess as long as they can "grab" onto a rock nearby, the sand shouldn't affect them. I may move them a bit lower then...