Hammer acting up, Need some input

Romeo_Reefer · Mar 25, 2025

I have a 32 g cube that I set up 3 months ago. I have some livestock in there

Corals:
1) Torch
2) Zoanthids
3) Chalice
4) Star Polyps
5) Hammer
6)Anemone

Fish:
1) Pair of clowns
2) Mandarin

Cleanup crew (mixed bag of some snails and red/blue hermits)

Water parameters are OK:

	9-Mar-25	14mar254	21-Mar-25
Salinity	1.025	1.025	1.025
pH	8.5	8.4	8.4
Alk [dKH]	8.4	8	8.3
Ca [ppm]	415	410	420
Nitrite [ppm]	0	0	0
Nitrate [ppm]	10	5	5
Ammonia [ppm]	0	0	0
Phosphates [ppm]	0	0.015	0.015
Magnesium [ppm]	1140	1140	1140

Everything else is growing and loving life. But the hammer is not doing so good, polyps are not extending, I'm not sure what's going on. He is in a med/low flow area about 2/3 down in the aquarium under FeeFi lights running at about 60 Watts.

Any suggestions of what's wrong? BTW I do not see any pests, and I do 5 gal reef crystals every week, with no skimmer.

KrisReef · Mar 25, 2025

Magnesium is low.
Are these parameters before or immediately after the 5 gallon water change?
(Nice table)
A photo of the hammer would help evaluate the coral.

Romeo_Reefer · Mar 25, 2025

KrisReef said:
Magnesium is low.
Are these parameters before or immediately after the 5 gallon water change?
(Nice table)
A photo of the hammer would help evaluate the coral.

I might have to dose Mg separately. I do use All for reef but don't want to overdose anything I don't need. Would a small Mg deficiency cause a hammer to recede? I'm at work now but I'll take a pic when I get home. But as a description, the hammer tentacles are only 1-3 mm outside of the skeleton with a clearly visible outside periphery of the skeleton.

BryanM · Mar 25, 2025

Romeo_Reefer said:
I might have to dose Mg separately. I do use All for reef but don't want to overdose anything I don't need. Would a small Mg deficiency cause a hammer to recede? I'm at work now but I'll take a pic when I get home. But as a description, the hammer tentacles are only 1-3 mm outside of the skeleton with a clearly visible outside periphery of the skeleton.

Randy would probably say your mag is likely fine.

Just say NO to magnesium testing: RMM is born

OK, this thread has been many years in the making, and I'm posting it here since folks in the chem forum are probably already tired of all the threads relating to problematic magnesium testing. I'm going to propose a method, let's call it the Randy Magnesium Method, or RMM for short. All good...

www.reef2reef.com

Any chance you have a reef safe with caution tank mate that has started to bother it?

Romeo_Reefer · Mar 25, 2025

Just two clowns, mandarin, and a skeleton crew for cleanup.
Nothing pasting the hammer as far as I can tell. I have the tank set up in my home office so I see it half the time.

Mr. Mojo Rising · Mar 25, 2025

How long have you had the hammer? Sounds like its in a location in your tank it doesn't like..... if everything else is happy, I would probably try moving it, maybe into a bit higher light...

Romeo_Reefer · Mar 25, 2025

Mr. Mojo Rising said:
How long have you had the hammer? Sounds like its in a location in your tank it doesn't like..... if everything else is happy, I would probably try moving it, maybe into a bit higher light...

That was my next question. Since the torch is happy, should the hammer be more or less light? Right now it's a bit more.

Romeo_Reefer · Mar 25, 2025

I've had the hammer for about 3 weeks.
Here is the relative position in the tank:

08TRDOFFROAD · Mar 25, 2025

I would try moving it down and off to one side or the other. The center area is likely where the PAR is the highest.

BryanM · Mar 25, 2025

Romeo_Reefer said:
I've had the hammer for about 3 weeks.
Here is the relative position in the tank:

Flow is decently hitting it?

My hammers don’t seem to care what height I put them at..

Romeo_Reefer · Mar 25, 2025

It was in a higher flow area and was getting receding. Maybe I'll just set it down on the sand for a day or two see if anything improves.

Romeo_Reefer · Mar 28, 2025

All right, I moved the Hammer down a bit and it started opening up again. Looks like it got a second wind. I should have know better but just didn't think of it.
I replaced the lights to be more on the blue / violet spectrum and forgot that they provide a lot more bang for the same watt since they penetrate more.

Romeo_Reefer · Mar 28, 2025

The blues just hit harder:

Shirak · Mar 28, 2025

uh yea but your tank depth is at the very top of that chart and insignificant. The problem is more likely your nutrients and perhaps low Mg. Especially phosphate at 0 or essentially 0. There is no hobby test kit that can measure phosphate accurately to .015ppm

Romeo_Reefer · Mar 28, 2025

Shirak said:
uh yea but your tank depth is at the very top of that chart and insignificant. The problem is more likely your nutrients and perhaps low Mg. Especially phosphate at 0 or essentially 0. There is no hobby test kit that can measure phosphate accurately to .015ppm

I agree that there might be a chemical cause. But the smaller wavelengths penetrate more even at low depths. All things being equal a 420 nm wave has less degradation then a 600 nm wave. So at the same wattage more blue hits a coral at 24" then yellows.