My Acros are browning, and I suspect hydrogen sulfide.

[Greg Hiller]

I doubt that hydrogen sulfide is really the problem. Yes, if you suck out some sand it will smell bad, but the hydrogen sulfide that forms in the low oxygen zones is very effectively oxidized immediately above the sand as it diffuses out. That said, high nutrients might be a problem in the tank. Reduced water flow is the usual problem that I have as colonies get big. If I do not make sure the water flow is good colonies start to suffer.

 

[serwobow]

Probably flow has something to do with it. I had the wave mode going for a few months up to the browning, and that doesn't really cause much flow with my pumps. I have since increased the flow. i guess I should look for some more ways to increase flow further because I am still getting a lot of organics settling at the bottom of the tank. At least now I can see the piles of gunk and siphon them out. For the last several years, those piles have just accumulated and mixed with the sand.

 

[goggs99]

Acros are like old fashioned canaries in a coal mine when trouble is in the air they go first...or let's say water