Hello everyone:-) I have a 29 gal bio tank set up for reef system,with a few corals and fish, assorted mushroom pollups, a frogspawn coral, a toad stool and a hammer coral which all seemed to be doing well, but about three weeks to a month ago my hammer coral's stems seemed to have changed color from brown to an opaque white, the tips are still green and all the other corals and fish are doing fine,so I was wondering if anyone has seen or heard of this before? signed Confused?:roll:

Would you have a picture?

I've seen torch corals that are white but i have never seen a white or to be honest a brown hammer.

could be a color morph from the lighting it was under to your lighting. then, it could be a lot of things, so i pic would really help.

What type of lighting do you have? If i remember right the 29bio comes with 65watt?

west, guess i could have asked that huh ??!! its been a long day !!

I will try and post a good picture this evening and get more lighting info! thanks so much. This sight Rocks!

Here is a pic of my strange color changing Hammer coral..my lighting is what came with the bio cube, one 36w actintic and one 36w 10,000k day light I think is what they are called.I hope this coral is ok?

It looks like your hammer is reaching for more light. The reason for it becomming a whitish color maybe due to not enough light. Try moving it higher up in the tank. The brown color usually means zooaxanthalle. Your color may be bleaching.

Hmmm..well i had it up high like the Frogspawn coral before and then after the color change someone recomended that it may be getting to much light and to try moving it lower?....and what is "zooaxanthalle"? :-)

Frogspawns and Hammers are 90% photosynthesis 10% filter. (ball parked for the visual) Photosynthesis is defined as using sunlight as the source of energy. Theres more there but i just used that to get the point across. Now frogspawn and hammers need this light to survive and grow, without it they will stay neutral growth and depend on feeding for energy. This can either to a coral that doesn't grow or bleaching and death or just death. Now I'm not sure how long you have had them and what you feed your tank for filter feeders but if it was bleaching at the top of the tank it was under alot of stress. Either major temp changes or not enough light and so on. My recommendation is pay attention to its surroundings and possible stress situations. I would also move it back to the top of the tank but somewhat slowly. How long are your lights on and how do you do water changes?

Also zooaxanthalle is the algae that lives with in organism's such as inverts that need light in order to strive. They basicly make up the frogspawn and hammers

This is how i understand it and if anyone has anything to add or argue please fill us in. :)

i would say bleaching as well. but im no pro. but i had some corals doing that too ..starting to go clear. and that was because either no trace elements or i wasnt shaking my phyto and zooplankton. even though youre kinda down and this may not be the right time, i think if it were supposed to look like that...thatd be pretty cool

Hmmm. yeh I started shaking up Trace elements back about a month or so,and as far as the lights there on for about 10 hours a day, which I thought was mabey too much because I was getting some green alge on the rock and glass, it probably doesnt help that I have the tank in a room that gets a decint amount of sunlight. Well thanks for your segestions,and if you can think of anything else,please let me know..:-)

i had a hammer and a torch frag that changed color EXACTLY likes urs. this was back when i have no MH and the tank was still new. now my hammer and coral are brown on the branch and green on the tips.. every parameters are acceptable. i have a 20 gal wt 150w MH and 65w actinics. my MH are on 8 hrs a day and my actinics are on 10 hrs a day.