Black rock

[fishfanatic2]

In order to get rid of a long-term hair algae epidemic, I threw 2 rocks in a bucket for about 5 weeks with a heater on for about 3 of those weeks. I put a black garbage bag around the bucket to prevent any light from getting in. I have been checking on it progressively and this is the first time I checked it in about 2 weeks. Well, I was kind of surprised to see that the rock is stained black. Almost all of the hair algae appears to be dead or dying (I would hope) and it smells reall bad. There is a layer of black crud on the bottom of the bucket, and what looked like to be small snails crawling up the sides. Is the rock ruined, and what happened?

 

[Len]

It's sulfur. This happens when you don't aerate the rock sufficiently. The rock is still salvagable, but I'd act quickly. Rinse and gently scrub the rock in new saltwater, replace the water in the bucket with new saltwater, and then restart the curing process .... this time with a lot of aeration/water movement.

 

[Anonymous]

I won't be as freaked out as Len, since it is pretty "normal"

The color is from bacteria that works with sulfur. If you are near any beach, try to dug a few inch below the water line, and you will see all the sand are black.

But, yeah, you need more circulation for the bucket.

 

[fishfanatic2]

Will 200gph of flow w/ aeration in a bucket holding about 3 gallons of water be enough? Thanks for the quick replies, I'll be rinsing it out today.

 

[Len]

I'd say in 3g, it should be okay. More is better/safer, but with an air stone, you should be fine. Decaying matter consumes A LOT of O2, so you need more movement and air then you'd normally would in a "living" system.

 

[fishfanatic2]

I started scrubbing, and WOW, this stuff is nasty. It smells like waaaaaayyy low tide at the beach, which is I guess essentially what it is. Anyway, the only thing I can get through scurbbing is a medium-light gray. Will the rest come off with circulation, or is the rock too far gone? And what about leaving it out in the sun? Would that work?

 

[Anonymous]

Don't overwork on this. The color is from the sulfur bacteria, and once the bacteria die (due to too much oxygen), the color will disappear gradually. The rock is fine, don't waste too much time on it in scurbbing it.

 

[fishfanatic2]

Ok, thanks. I have the pump going, so I'll wait and see. Worst case, it's only two rocks.

 

[Anonymous]

I just opened a bucket of rock that had been sealed for about 1 year. No heat, no circulation

They were all black, and so was the bucket. I rinsed them with a garden hose for an hour, then hit them with a power washer. Now they're in a bucket of water change water with a pump (and soon to be heater)

Most of the black stuff came off with the power washer.

I was completely amazed that there was STILL algea growing on the rocks after a year with no light/movement/o2

So In a few months, I'll have some new rock for my tank!

B

 

[fishfanatic2]

The power washer really helped, about 97% of the black is gone and most of the hair algae is on its way out. I now have it in a bucket with a pump/aeration. Hopefully the cook will soon be done. Thanks all!