Why did my live rock turn brown?

Question

New tank (3 - 4 weeks)
3 damsells
original piece of rock turned brown & flaked all over tank
the newer pieces are still colorful
20 gallon tank
3 stage filtration system
using reef complete

Answer 1

Probably you've got an overgrowth of diatoms or a brown algae. Compare what you've got with the photo a short way down this page: http://www.wetwebmedia.com/brownalgcontfaqs.htm

You can get some of the info from following the discussion in the forum, but if this is a diatom bloom, it shows a higher level of silicates in your tank. Some diatom bloom is normal and will disappear as the tank matures, but if the problem is within your water source or salt mix, it will continue. You can also control this through water changes or a protein skimmer (reduces the nutrients on which they feed), lighting (turn off lights unless you've got macroalgaes you want to survive), and circulation (increase it by using powerheads). A good cleanup crew (hermits, snails, others) may also eat some of this. If you can identify this as a diatom or a particular brown algae from this link: http://saltcorner.com/sections/guest/algaepage/algaepage.htm use the number next to name for your algae to locate an organism at the bottom of the page which will eat that.

Answer 2

The inhabitants on your live rock died, which is to be expected since they are very delicate. It's okay, though, it will help to cycle your tank. Better to lose inhabitants on your rock than fish. You didn't tell us what kind of lighting system you have. Many inhabitants of "live rock" may be of the coral species and algae, they need a lot of light. Your newer pieces may also die since your tank is so new. It is a slow process, try not to push it, once your tank cycles, you can remove the "dead" rock and replace it with new "live" rock. I know it's expensive, but it is a learning experience.

Just remember to check the PH level, nitrite level (which will be high in a new tank which will kill some live rock inhabitants), nitrate, and salinity. You will get the hang of it once you see how your aquarium reacts. Good luck, don't lose faith, once your tank cycles, you'll be fine. It's so much fun.

Answer 3

I think he's dead. Sorry.