LR dead material question

[hardin4019]

Hi Guys, I have a LR question.

I got my FOWLR from a co-worker who could not keep it any more. He did not keep the light on more than just a few hours a day and at strange times. When I got the tank from him, and still now, there appears to be lots of dead or at least dark brown or black material covering the surfaces of the rock not under the sand line.

Once I got it home and up and running, I put a 10 hour timer on the light. The rock eventually started to get some dark green and dark purple velvet colors to it. I eventually started to see some coraline algae colors on areas that didn't have the dark material.

Since then, my fish got ich, I've removed all the LR and crushed coral gravel, put them in a tub with a HOB Filter and Heater to keep the cycle of the bugs going nearly the same as the display tank.

The question comes in, should I do anything to remove the layer of what appears to be dead material on the rock before I put it back in the display tank, or leave it? The one other thing that comes into affect that I can think of is that the single 40W Power Glo bulb is probably 2 years old and could greatly use replacing.

I eventually want to add better lighting like 216w quad T5 light and get a nem and eventually coral.

[hardin4019]

Bump. Anyone?

[tmz]

The blackish stains on rock that was under the sand line are probably sulfides which should do no harm. Did/do they have a sewer gas odor? Sulfides are a product of oxidized hydrogen sulfide (which is formed by sulfate reducing bacteria in anoxic areas when organic carbon such as material on the buried rock is there).

[hardin4019]

From above the sand line though... What was under the sand line has a pretty normal color and even showed some coraline algae color with the lights on the timer and being exposed. No bad smell, just a soft smooth feel.

[tmz]

Alternatively,a picture of the balckish material would be helpful. If it can be pulled or scraped off then it might just be decaying sponge or some other organic material which to the extent it's practical should be removed..

[hardin4019]

Under the sand line side of a small piece, aside from a bit blurry, you can see the purplish algae growth still doing ok in a tub for a month now with no light beyond the day light coming in the windows:


Opposite side of same piece. Tank was filled with horrible layer of black stuff over the sand (we tossed out) when it was given to me:

[hardin4019]

Anyone else?

[hardin4019]

Bump

[hardin4019]

Tooth brush really didn't do anything. Some areas it is a thick stuck on material... It can be scraped or picked off. My best bet appears to be a dental pick. Anyone have an idea what it is? Maybe I the info about what the tank looked like before I got it would help. There was a thick (1-2 inches) layer of black dead material on top of the sand and the rock is basically in the same shape.

[blynch002]

Wish I had an answer for you but I can tell you that I had the same problems when I got my tank from a friend. I tossed all of the old sandbed and used one of those weird grooming tools my wife had laying on her vanity (not a good idea to ruin the wife's beauty products) but it worked and also lowered the ammonia in the tank. I had a bad ammonia spike and the best I could figure it was from all of the dead and dying organisms on the live rock. So I definitely suggest removing the gunk from the rock before you have the same problem I did. Good luck!

[mrabolli]

Cook it.

[hardin4019]

Wish cooking it were a better option, but with the exception of the small pieces, I don't have anything big enough to cook it in. I have basically a 40g breeder size plastic tub filled with live rock right now. Most of the pieces are basketball sized. Plus, I'm really impatient. I'll try picking some of it off and see if maybe there isn't a cleanup crew that might pick the rock clean.