[Dubes]

I have two branching hammer corals which I have had for about a year. Both of them were growing great with new growth on them. For the past few months though, they have turned white and the green tips have faded and the tentecles have gotten really skinny and are shrinking. Anyone have any ideas why this may happen. I have a 180 gallon tank with 4 50/50 96 watt PC. Water quality seems to be in order. I have about 25 other different types of coral both hard and soft and all others are doing well. Any help would be appreciated.

[Reefland]

Hi Dubes and Welcome to Reefland!

I have a couple of thoughts for you. First, do you ever offer direct feedings to the Hammer Coral? Like brain corals, Hammer Corals should at times be fed to provide the energy they need to survive.

My second thought would be the lighting. 4 PC's over a 180 gallon tank isn't much at all and you may be starting to see the long term effects of this. Have you changed these bulbs lately; how old are they?

Scott Z.

[scubadude]

As well as what Scott mentioned...are your hammers crowded? They can sometimes appear to have adequate room until you look at them at night they usually send sweepers after the lights out....maybe they have outgrown their area? Have you done any recent changes to your system? like flow? or add more corals? Turning white does sound like a lighting issue though just adding some other possibilitys

[Dubes]

Originally Posted by Reefland

Hi Dubes and Welcome to Reefland!

I have a couple of thoughts for you. First, do you ever offer direct feedings to the Hammer Coral? Like brain corals, Hammer Corals should at times be fed to provide the energy they need to survive.

My second thought would be the lighting. 4 PC's over a 180 gallon tank isn't much at all and you may be starting to see the long term effects of this. Have you changed these bulbs lately; how old are they?

Scott Z.

thanks for the information. I have a question. i did make a change in the lighting and I don't know if it is different. the store I went to said it should be the same. Basically, when the corals were growing and doing well, I had 2 96 watt PC daylight bulbs and 2 blue actinics. I switched to 4 50/50 s so that the light would look more even. are the 50/50 bulbs equivalent in light as the blue and daylight solid bulbs?

[Reefland]

Yeah they really shouldn't cause a problem. When were the new bulbs added and how old were the old bulbs when you replaced them? If you noticed your corals reacting like this directly after adding the new bulbs then there is your problem and you have a couple of choices.

Place some screen just below the lights to shade the corals a bit.
Decrease your lighting photo period for a couple of weeks, slowly working it back up to what it is now.
Move the corals to a shaded location.

Scott Z.

P. S. I should clarify a bit more. The problem isn't with the type of bulbs, it's with their intensity. Obviously as a bulb ages, it loses it's intensity and when you add new bulbs, the lighting intensity increases and shocks the corals if they are not acclimated to the change slowly.

[Poseidon]

This is just an opinion, but when I had PC's I liked the look of 2 whites 2 blues better then 4 50-50 bulbs... The tank seemed "brighter" plus it was easier to do the Dusk to dawn with actinics coming on first off last type thing. I would personally try and Shade the hammer a little..

[Dubes]

Originally Posted by Reefland

Yeah they really shouldn't cause a problem. When were the new bulbs added and how old were the old bulbs when you replaced them? If you noticed your corals reacting like this directly after adding the new bulbs then there is your problem and you have a couple of choices.

Place some screen just below the lights to shade the corals a bit.
Decrease your lighting photo period for a couple of weeks, slowly working it back up to what it is now.
Move the corals to a shaded location.

Scott Z.

P. S. I should clarify a bit more. The problem isn't with the type of bulbs, it's with their intensity. Obviously as a bulb ages, it loses it's intensity and when you add new bulbs, the lighting intensity increases and shocks the corals if they are not acclimated to the change slowly.

yeah the bulbs were about a year old when I changed them, However that was about three months ago, and the hammers have been doing poorly ever since. Do you think it is too late to shade them now. I can try to do so however, I was under the impresstion that hammers needed lots of light. I have a grape coral that reaches all the way to the surface of the tank and it is doing well. i will give it a shot though. thanks for all the help from everyone.

[Reefland]

Hammer corals do like a lot of light but with any coral, if they are acclimated to a bulb and when it is a year old, it has lost a lot of intensity. When you replace bulbs, you replace that lost intensity and the change can shock and distress the coral. If it's been 3 months since the change, I don't think shading it now will help. You might try to offer it some feedings to see if that might help.

Scott Z.

[Poseidon]

Bummer... I think you def. should shade it, maybe move it partly into a cave or under a rock shelf... No need to shade the hole tank now. Just try and help the Hammer