MH question

[powdertang05]

ok my LFS was explaining that his corals are under 20000k MH and vho actinics also/ mine are under 10000k and vho actinics he says my corals will sometimes addapt to the light others will just die what the heck is that right em i retarded also how should i be under if i want good growth in my sps's and another all sps's except a bird nest are happy always out but its like bleaching and loosing its skin im freaking out this is soo hard to keep loosing 100's every pop what em i doing wrong?

sg 1.025
am 0
nitrite 0
nitrates 2-4 sometimes 0
PO4 0-0.1
protein skimmer asm mini moded with a genx1500
40gal breeder
20L sump
feed only what they can eat no more water is clean and clear what is my problem. this is killing me!

[Blown 346]

Corals will adapt to 20 K just like they would to 10 k.
The reason for this is where the coral is placed, if it is too close to the light the oral will bleach and turn white. If the coral is far from the light and isnt getting enough it will bleach and die.

One question that is overlooked is the age of the bulbs.

Are your bulbs old ( over 8 months) If so, if they are lit for 8 to 12 hours a day, they need to be changed.
Halides can last up to a year, after that there intensity and lighting spectrum decreases by almost half. Corals will react by bleaching from not enought light.
They will also do the same thing if new lights are installed, they do this from the shock of the new intense light.

If the corals are placed too high or arent slowly adjusted to your lighting they will show signs of bleaching.

[dberlin]

Your 10k lights are MUCH stronger than the stores 20k lights. You will need to carefully acclimate any corals slowly. Start everything out at the bottom of your tank and slowly, over a period of a few weeks move them up. Keep an eye on them for any signs of too much/too little light.
If you take your time to acclimate them most corals will adjust fine.