Zoas color darkening

[Nht8134]

Hey guys. Im having some problems with my zoas. Now Ive heard of zoas "losing" their colors and bleaching but have you guys heard of zoas bright colors turning dark? I have some orange crushers(1st pic) and eagle eyes(2nd pic) that are supposed to have bright green skirts. Ive had them for about a month and they have turned dark brown. Is this normal? I believe it was under MH in the original owners tank and now it is under PCs.

If it is normal, then will the colors come back? These are one of my favorite zoas and I love the bright green skirts the most about them. Thanks for your replies.

 

[Reef Junkie]

Usually high nutrients and low alk cause corals to brown up.
Try running carbon or a poly filter and test your alk. If it's low (in the 2's) bump it up to the 3's.

 

[Nht8134]

I have been running carbon for about 3 months now. As far as nutrients, nitrates, trites, and ammonia are at 0. I just tested my Alk with the Red Sea test kit and it was 2.9-3.6(thats in range right?). What else could it be?

 

[Reef Junkie]

how's your phosphate?

2.9 to 3.6 is a broad range. 2-3 is low end 2.5 to 3.5 mid and 3.5 to 4.5 high. Where are you? 2.9 or 3.6?
How old is the test kit?
Try a salifert kit, they're pretty accurate.

 

[stevemc]

If they were under MH lights especially 10K, then yes they will get darker, but they might come back, never as bright, but usually a bright color. Remember PC lights are normal output and MH lights are high output, so the intensity from them will never be met by normal output lights. Some zoas need real intense light. Usually if they were collected originally right near the surface in shallow water-they need real powerful lights, but could live and get used to low power lights. Some really do well and color up under PC, T-5 and T-8, even shop lights with sunlight bulbs. It seems like some really get bright and sort of light colored but very bright under 400 watt 10 K Mh bulbs-like the green skirts are yellowish florescent green. But under 20 K lights they seem to get very colorful and not so bright -skirts get very bright green. VHO lights seem to make them bright. Combos of 20 K MH and VHO bulbs seem to make them very, very bright and colorful.

 

[stevemc]

And like they said higher range alk seems to make most corals bright.

 

[Reef Junkie]

Bulb temperature plays a role in coral coloration, but should not dictate the overall color of the coral. Enviromental conditions like alk play a much bigger role. I have seen corals under PC's and MH look the same. Some of that depended on Watts per gallon and depth of coral placement, though.
Most of it boils down to husbandry.

There is also such a thing as too clean. Zoanthids do not like the aggressive use of carbon.
Have you removed it yet?
How often do you change it?
How much do you use?

 

[Nht8134]

I bought a different carbon hardness test and it tested alk tested at 9 dKH. Is this the proper range for alk? I have a lot of other zoas and they all do fine. Im only having problems with my eagle eyes and dragon eyes with the supposedly bright green skirts. All of my other zoas have beautiful colors. But why are the greens the ones IM having problems with? They are my favorites. Please help....



BTW....Im not using any carbon at the present time.

 

[Reef Junkie]

9dkh is within a reasonable range. It's even good.

I would begin with some water changes. Maybe 10 to 20 gallons, depending on your tank size. Start with 10 gallons tonight and another 10 in 2 days from now.

Last ditch is if the corals begin to recede, frag them and let a friend hold them until you figure out the problem.

 

[Psychographic]

I would bet it's your PC lighting. I run PC's and some of my Zoa's are not as bright as they were under Halides, I also have some that have colored up better under the PC's than Halides. Some like intense lighting and some don't.

 

[Nht8134]

Its not so much that its not as "bright". There is noticeable "browning". Its changing color.