HELP!! Bleaching problem


New member
Ok, so here is the deal. for the longest time I had a PFO 150 watt DE MH over my tank, and everything was great. However, I had some shading in the sides of the tank, so I built a great reflector, and got a 250 watt coralvue setup with a 250 watt SE reeflux 12k. I put the new light on, and raised it up a good ways from where the old one was. after a few days, I noticed some SPS getting pale. So, I raised it up even more, and shortend the light period by about 2 hours. Anyhow, I left town last thursday and got back today, and I have lost 2 SPS colonies completely to bleaching. My largest colony is almost completely bleached (some remaining color toward its base), and a couple others are really bleaching as well. I raised the light even more (probably24" above the water surface now) and shortened the light by another hour (only on about4 hours now). I also moved the mostly bleached SPS to the bottom of the tank.

What should I do?

Why are some of these bleaching so much eventhough I raised the light and shortened the time period?

Will they recover


Premium Member
They can and usually do recover if they haven't been stressed too far. I've seen it happen surprisingly fast, too. You might consider going to the hardware store and buying some window screen and layer it over the top of the tank to make some shade, then gradually remove pieces over a period of a few weeks to adjust them to the full strength light.


Premium Member
Increase your flow and decrease your lighting. Window screen is a good idea at this point. Reducing the photoperiod really doesn't have much effect, since it's the lighting intensity much more than the lighting period that does damage to the zooxanthellae.