lighting issue

[coolreef]

i put a 150w mh light on my 29g biocube and it seems to b burning up my corals. i tried to aclimate the tank for the new lighting by only leaving it n for a few hours a day, is this just too much lighting of ami not acclimating properly.

[Juiceman]

Check your temperature when it's on. That would be my biggest worry. And do only an hour or 2 at the beginning. Hope for the best! Take you time!

[Timfish]

+1 on the heat. Heat would be the first thing I look at but it can take a long time for corals to adapt to higher light levels, as in 4-8 weeks or longer. It will vary depending on the species and the conditions it was growing in, some species are highly adaptable some are not. It's also a less likely possibility with the brighter light your colonies don't need as many zooxanthellae and have paled as a consequence. If your corals are going completely brown and losing the flourescing pigments after several weeks there's either been a big change in the spectrum as these pigments are sensitive to just one wavelength or I would think in your case the lighting may be too intense. Sunset monti's are one example that comes to mind that lose their green and orange pigmentation under bright MH lights. (And of course to confuse this issue are corals like a lot of the acros that go brown under lower light levels and lose their bright colors.) If you rule out heat as an issue find people who are growing the same corals you are and compare notes with them on the lighting conditions they are keeping their corals under. If you can look at their tanks a cheap lux meter (admittedly a PAR meter would be better) can give you a good idea if your lighting is in the ballpark for your corals.

[medi]

Definitely not too much light for that tank. I ran a 250W MH over a 34G for over a year without a problem. I would definitely monitor your temp, and also how old is the MH bulb? What brand and K is it?

[jestep]

Do a 2 or 3 day blackout and then start with an hour per day. Increase by 30 minutes every 4 days and you should be ok. Heat is a big issue though. Make sure the tank isn't going over 82 during the day. If you have any supplemental actinics, you can run them for 8 hours per day in the meantime.

[AquaJohn]

you can also use egg crate as a light defuser oh wait thats what eggcrate is lol. it will dim the light. You can also add **** I cant think of what it was called but its like a window screen or bird net for trees. just has to be all plastic so it does not rust or add bad stuff to your tank start with like 3-4 sheets and each week remove a sheet.

[coolreef]

my tanks sits at about 80-82 during the day with the light on it doesnt get any hotter than that though and cools when the light is off i think ill try the black out method along with some egg crates is that temp too hot? should i look into a chiller? if so what size would i need?

[jestep]

If you're not breaking 82, most coral should be ok. Make sure your night temp doesn't swing too much. Swings are worse than slightly high temperatures. You can also put a cooling fan to blow air across the water under the MH. The evaporation cooling as well as removing the radiant heat from the fixture will make a huge difference if you aren't doing it already. Also don't underestimate how long some coral take to acclimate to new conditions. Some people recommend more than a full month when switching to a higher light fixture.

[coolreef]

thanks for the advice im currently working on acclimating everything to the new lighting ill let yall know how it goes.