Hammer with receding head

[Zalick]

Background on my hammers:
I've had my current 300g tank up for about 18 months. For lighting I have 6 Kessile a360W. Flow is two gyre 150s on opposite ends, pulse mode, about 30% power, plus my sump return of about 600gph. My lighting schedule is a ramp from 5am to 6pm, with full power and color for 7hrs mid day. I have two different hammer coral.

One piece I've had for about 4 years or so. Started with 3 heads and now is about 40ish in 3 seperate pieces. It went from my old tank to the 300g about 1 year ago. Its grown quite a bit during that time under the kessils and with the gyres. It has about 20+ new small heads growing.

The other hammer, pictured below is about 3 or 4 months.

I had the placement about mid tank for both corals, with moderate flow.

A few days ago I noticed a single head on the new hammer was receding and the skeleton was showing as seen in the pic. The other heads were fully extended. I moved it down to the bottom of the tank and took one of the kessils offline so its getting the wide rays from the other kessils and not directly blasted. The receding head opened a little and some of the polyps extended but still lots of exposed skeleton.

My old hammer just showed a head doing the same thing, so I moved it to the bottom too. Now tday a second head on the new hammer is doing the same thing.

I have not observed any fish harrasing them ever. Not during the day or at night. I have not seen any types of parasites on the coral.

parameters:
PH: 8.2
Alk: 7.2
Temp: 79.5
Phos: 0
Salinity: 1.025
Calcium: 425

I have not measured iodine or magnesium. My cleaner shrimp molt frequently, so I imagine iodine is good.

SPS, soft corals, fish and inverts are all healthy and looking good.

I have not made any recent changes or additions to the tank with the exception of some plastic gutter guard like material that I put across my overflow to keep my lawnmower blenny from going over. This has been up for at least 60days.

I did change out a canister of GFO last weekend and I imagine there was a slight to decent phosphate drop. I know hammer likes slightly dirty water. I have a healthy amount of algae, so I know the phosphate levels were good. The algae is slowly dying off with my GFO routine, but not rappidly. I doubt the phosphate drop would cause this but could it?

Does anyone know what might be causing the heads to do this? I really don't want to lose the 40 heads on my 5 year old hammer. It was the first piece of coral I bought when I got back in the hobby after a long hiatus.


Thanks for the help!

 

[Dkuhlmann]

Just to be on the safe side I'd iodine dip them as it could be a bacterial infection, which they get if something nips at them or hits them. Doesn't take much damage for the infection to set in.

Here is a link to doing iodine dips for bacterial infections in corals.

http://www.athiel.com/lib/bacterial.html

 

[Zalick]

Just to be on the safe side I'd iodine dip them as it could be a bacterial infection, which they get if something nips at them or hits them. Doesn't take much damage for the infection to set in.

Here is a link to doing iodine dips for bacterial infections in corals.

http://www.athiel.com/lib/bacterial.html

Thanks! I'l give that a try tonight.

 

[Coralmassa]

I heard euphylias are prone to bacterial infections as well. With hammers I've never had success reviving a distressed head. I usually cut off the affected head if it's clearly not going to make it and I dip the rest. If took care of a tank that was all frogspawn, octospawn and hammers, probably 500 plus heads, and even though the owner pretty much neglected his tank, he had a bunch of clowns hosting them like anemones . They probably benefitted from all the poop

 

[Dkuhlmann]

You do realize that a hammer is a Euphyllia? IMO and IME any Euphyllia head that still has tentacles on it is worth trying to save by dipping in iodine. But I guess if I was dealing with a tank of 500 ish heads I wouldn't care either and just cut them off.

 

[louscal]

I'm going through the same thing right now I am going to try and dip it tomorrow and see if I can save it mine is not showing as much skeleton though

 

[Tweaked]

You do realize that a hammer is a Euphyllia? IMO and IME any Euphyllia head that still has tentacles on it is worth trying to save by dipping in iodine. But I guess if I was dealing with a tank of 500 ish heads I wouldn't care either and just cut them off.

This!! In addition what we see in our tanks is usually a problem weeks earlier and you see the issue later only compounding the confusion. Can't stress stability enough even if it's wrong (i.e. Low or High) We typically want to rush back to the numbers we were at but you need to go super slow. IME it's alk that wipes out coral with stony base.

 

[organism]

I did change out a canister of GFO last weekend and I imagine there was a slight to decent phosphate drop. I know hammer likes slightly dirty water. I have a healthy amount of algae, so I know the phosphate levels were good. The algae is slowly dying off with my GFO routine, but not rappidly. I doubt the phosphate drop would cause this but could it?

GFO doesn't just drop phosphates. If you add too much at once it can also drop the alkalinity pretty quickly, which leads to LPS issues just like the ones you're seeing. imo Euphyllia are some of the touchiest LPS as far as alkalinity swings go. I would bump up the alk to 9ish and see if it makes a difference, water change couldn't hurt either.

Also make sure they're getting enough flow.