frogspawn in trouble

[tasos]

my frogspawn frag seems not to do so well latelly, after more than 2 weeks of staying healthy in my new (from August) 125 Gallon system with remote dsb, chaetomorpha and no skimming......Sps frags are growing, and the only thing I changed is the addition of moonlight leds, and some (around 5ppm) KNO3(potasium nitrate ) to boost the caulerpa-chaetomorpha in the refugium..
What might have stressed the coral?Alk is 3,3 meqV.
Do the euphylias have problems with the K ion?(potasium).The nitrate levels are still not meassurable-my refugium eats them all!!

[Justin74]

So from what I can tell of you briefly touching down on your system, its seems as though you have a very good handle on water quality, if you pH is fine, your phosphates are undetectable,your calcium is 390-460 and your magnesium levels 1300+ then I think we should move on to lighting and flow and how much of both this guy is getting.Then next what are you supplementing its nutrition with other than light?

-Justin

[eugeneK]

mine hates when my alk drops that low, opens back up when its around 3.6 ~~ 9.9-10 DKH

[tasos]

Álkalinity seemed to be the problem,as the coral opened better when I added some more buffer....The lighting is OK I suspect with 4 T5 14K tubes 54 watt each and 2 actinic ones above the 100 gallon main tank!!Ca:400ppm, Mg:1200 ppm.
Thanks guys!!