Thinning SPS tissue typically a sign of??...

[spsfragur]

I'm a little at loss. Lately, (last 3 weeks) my sps have decreased polyp extension and their tissue seems to be thinning.

No bite marks, splotchyness, etc. I've had AEFW, but it was a different tank, so do have experience with those effects.

I've cared for sps corals for 5+ years and just can't figure this out. No RTN or STN, tissue just seems thin, but if it continues I believe death will result. Not death in a STN or RTN way, but just it seems the coral would fade so much, the tissue would just dissipate. I know this sounds like crazy talk, but it is occurring to me. This is affecting a range of corals, montipora, strawberry shortcake, red planet, etc.

I run the basic system, 250 watt radiums, skimmer, water change 20% each week, small bioload, reef crystals salt, reef-safe fish, no nippers, etc.

I did add a small amount of chemipure elite to combat a little algae bloom, but run it passively in the sump so as not to shock the system....but maybe this caused some issues.

RODI water has 0ppm....I guess something crazy could have happened like electric current, lysol in the air, etc....but it seems in my experience those odd issues are never really the problem. Water changes doesn't seem to make a difference, tried a 50% the other day and a few smaller ones right after...

As for water:
Ammonia 0
Nitrites 0
Nitrates 0
Phosphates - no hanna
Alk - 9
CA - 410
Mag - no test kit....may need to purchase, but no signs of precipitation and do more than adequate water changes.
Salinity - 1.026
Temp - 78-79

With all this being said....has anyone experienced the thinning of sps tissue? What comes to mind when this occurs? Also to be clear, I am not referred tor thinning of branches that is often related to flow....but thinning tissue and no polyp extension.

I am open to ideas and thoughts. My first thought is to cut the water changes, and feed excessively to see if that helps, perhaps until nitrates reach 5 and see what happens....but then again, my corals are not necessarily pale....

thanks all

 

[fishguy597]

Pics please

 

[tripdad]

I get what your talking about. I have had periods where the acro's just don't look "plump" and filled out like healthy ones. Have been seeing a trend(?) of true ULNS systems keeping Alk at around 7.5 with better results, can't explain why scientifically but just an observation. Have you checked things like iodine, potassium , iron, etc.? definitely check that Mag, use you LFS for test you don't own. Personally I don't like all zero's on phos and nitrates, they gotta eat too.

 

[spsfragur]

Thanks guys for the advice, my apologies about no pictures yet, I will try to get some up, been swamped at work.

On a related note (I think), I decided to check the calibration of my BRS refractometer and it was off some.....I thought my water was at 35ppt, but it was actually (after calibration) at 31 ppt....not sure if this is related, but I will bring it up slowly. This sounds odd, but I am actually relieved to find a parameter off....i can't stand when corals don't well and everything tests out fine.

That being said, not sure a salinity of 31 ppt is really to blame, i suppose it can't help matters.

I will let my alk drop a little and feed some more and see how things doing over the next couple weeks.

 

[Dapg8gt]

I've recently been dealing with this and it in my case was from a faulty batch of ulr reagents.. Salinity being low can cause a slew of problems in a system fwiw.

I was chasing higher p04 numbers that were actually 0..I usually will verify new reagents with the current ones I am using but I failed to do it this time so for the last few months my p04 was reading .10-. 13.. I was ramping up gfo usage on a tank that didn't need it and the corals and colors suffered greatly..

I came to the conclusion that something was off and bought a few new batches of reagents and all measured 0 ppb.. Just a few weeks in and colors are improving and overall tissue health is on the rise. Having no measurable p04 in the water for so long caused me to lose a few colonies and color on almost every acro in the tank.. All the time thinking my problem was from high p04 .

I reccomend getting good test kits and verify the readings with something/someone else and keep your nutrients above 0(at all costs) and see how the tank reacts . I also follow the low alk route due to carbon dosing.

 

[jgalen0025]

try zinc additive slowly(from zeovit)

 

[dartier]

Have you checked things like iodine, potassium , iron, etc.? Personally I don't like all zero's on phos and nitrates, they gotta eat too.

I was going to suggest checking Iodine as well. I just came through a period that sounds like what you are experiencing (except my NO3 and PO4 are much higher). No polyp extension and the corals were merely existing and seemed to be weakening day by day. I tested Iodine and found it was 0.03. I dosed Red Sea Coral Color A to get it back to 0.06 and it made a world of difference. Within a couple of days I had poly extension and the bases were encrusting back over the receded parts.

I would check the lesser watched elements like Iodine and Potassium.

Dennis