Corals dying due to lighting

[chuppy]

Hey all.. i got a 10g all and pwered by a 20000k 150w MH light... so far.. i think this light is killig some of my new corals :(

I gotta know... what should i do?? My water params are all right... but i suspect it is due to sudden brightness that's killing some of my polyps and trumpet coral off... but the weird thing is.. my old trumpet coral thrives and splitting!

Is there a way/method which i don't know about which involves light acclimation? All my corals go trough 1 and a half hours of drip liquid acclimation... These 2 corals were fine when they were under a 150w in the 50gal in the lfs =(

It's placement is in the sandbed...

HELP!

Drew

[Demonic]

In my opinion, i may be wrong though. But MH's is too much for a 10gal tank.

[BangkokMatt]

Thats a lot of light for a 10g. How long do you have the lights on for ? More info about your params would be helpful. How stable is the system. Small tanks are prone to parameter instability.
However, if you think it is the lights I would take the lights down to minimum time for your corals. Maybe 4 hours a day. Then build them up by adding 15 minutes every week until you reach the desired time.

[3mm3]

Is your metal halide bulb a double end hqi? If so is the protective lens properly installed. Might be uv killing the corals.
I had this happen to me before.

[chuppy]

Well it is double ended... but the strange thing is... other corals are doing waay fine... just this particular new frags.. Demonic.. i did ask around the forum once but majority said it is good and even advisable lo.. i was rnning in 22w PC's before. ..

BangKok Matt... well now it is on 12 hour athnics from 9am to 9pm... while the MH is on for 8 hours from 11am to 7pm

To further clarify the water params.. well i'll post info after another test today.. but my prev test show all in order except a little nitrate... hmm.. Will post info later.

Drew

[kau_cinta_ku]

how close is the MH from the tank?

and to light acculimate them you can do 1 of 2 ways.

1. start the light off at half the normal time and ancrease the light by .5-1 hour every week till you get to your normal lighting times.

2. put 4-5 layers of the black windowscreen over top the tank and remove 1 layer every week.

[chuppy]

about 4 inches off as it is an open top and it is a clamp-on system

Drew

[yellowslayer13]

raise it to at least 8'' to 12''

[uscharalph]

Get a bigger tank.

[super stooge]

how about your temperature?

[chuppy]

Ralph.. as a fishkeeper of course i want! but i currently have a FW rack to finish... maybe in about half a years time :P

Super stooge.. my temperature is controlled at 25 celcius .. chiller installed :P even without mh temperatures here will soar to 30celcius without a chiller

Drew