Help me grow acros

[ctyler85]

been in the hobby awhile, had some great success, had some big failures. 265g tank. about 3 years ago had a big crash, alk spiked to 15dkh(dosing failure) and destroyed all my SPS. LPS were uneffected. then the kid was born and the tank got severely neglected. Im getting back into it again. All the LPS is still thriving(favia, favites, cyphastrea, platy, leptastrea, tachy). I used to grow sps and acros great. But since the crash I havent been able to keep any acros. The RTN after a few hours in the tank. took a break before trying anything new. got back on a water change schedule, cleaned the tank up. thought I would try an "easy" acro. Bought the frag on Saturday, and as of today its starting to RTN but the stylo frag I got the same day seems to be uneffected.
ammonia undetectable with api
nitrates undetectable with api
nitrites undetectable with api
alk 8.5dkh
calicum 550
magnesium 1500
ph 8.0
I know the calcium and magnesium are super high but I can not figure out how to get them down. Doing some reading through the forums it seems like maybe I have a nutrient deficiency? Any thoughts, input advice would be awesome. I need to get the tank dialed in before I go trying another frag. At this point I'm ready to start investing some real money to make this tank successful again

 

[lapin]

First, Invest in some better test kits. You want to be sure of your numbers.
I would also get a Phosphate checker. Hanna Ultra Low is a good one.

I would then try to get my calcium and mag numbers down. Not sure whats causing this (salt, dosing. ect ?)
Low nutrients with high cal and mag numbers have been know to cause issues. Rather than trying to add nutrients to match the high numbers I would reduce calcium and mag first. Then if your lacking nutrients, try to feed your fish a bit more.

Not sure if this would help in your case but its where I would start.

 

[ScottB]

Give you my thoughts:
a) as @lapin said, get the Hanna low range. Acros don't need much PO4, but they do need some always available.
b) Not sure about your fish load and nutrient export, but zero nitrates is a no-no. You don't need much, but you need some. More fish and more food.
c) Stop testing ammonia and nitrites. Just for the cycle.
d) Ca and Mg are no big deal unless you are actively dosing which I doubt.
e) acros that RTN within hours is something totally different than the above will correct. Describe dip/acclimation process and source of the acros.
f) Never hurts to send out for an ICP to rule out other things and confirm some of your test results. ATI or Triton.