Acro's

[Fishfreak]

I have a 180 gallon with mostly SPS corals. It has 3- 250W 15k Metal Halides and 8 blue t5's I just replaced the bulbs about 2 weeks ago. But I have noticed and this isnt the first time that the arcos flesh will start peeling off. Then in like 3 days it will be white and dead.    it hasnt happen for about 4 months but just yesterday I notice one of the arco's started doing it. Then one I just got Thursday is peeling. Im rly bad about just bring them home and floating them for like 30mins then just puting them in after I put them in coral Rx. Im not sure why this is happening but if anyone has idea please give me some input.
Parameters last I checked like last week-  Ca-400 Mag- 1275 Total Alk-3 and the salt level is usally right at 1.025. I know the mag and Ca are a little low and Iv been working on getting them up then planning on dosing Kalc. or adding a Ca reactor.

[kattz]

Going from old bulbs (dimmer or different color temp) to new bulbs (brighter or different color temp) can be a factor.

[lazylivin]

I am going  to guess it is due to you low alk. What is chances it is dipping lower than three at times.

[Fishfreak]

Well whats alk need to be? Someone keeps telling me (Total Alk-3.5)

[lazylivin]

There is a tremendous difference from 3.0 - 3.5.
3.0 is close to 8dkh and 3.5 is close to 10 dkh. A dkh of 8.0 to 12.0 is typically okay. Not saying it can fluctuate in that range, it needs to stay consistent. The most common loss of sps is due to low alk. I am thinking that if you are running on the low end of the spectrum then it is possible with a margin error and flucations occurring in a 24 hour cycle that it is possibly dipping to low. Also recommend getting the coral that is rtn/stn out of the tank immediately or frag off the good portion. This is because it is likely putting chemical signals in the water that has the potential of causing a chain reaction. Consider bringing your alk up to 3.5 meq/l slowly if not already. Also consider using dkh scale instead of meq/l because it gives a false since of being close to the target range.

[kattz]

Thanks, Lazy.  I was going to reference alk level this morning but was unfamiliar with the alk scale that Fishfreak is using.  I know my corals are loving the 1Dkh.

[kattz]

Make that 11 Dkh, NOT 1!

[Fishfreak]

thanks guys!

[Fishfreak]

Would a Ca. reactor help with keeping that level? Or would that only help with Ca and mag?

[lazylivin]

Yes a calcium reactor has the ability to keep the three major and many of the minor elements in the optimal range.