Sewage smell new tank?

[Heabel7]

I’m starting a new 40gallon tank that I plan to plum into my main 90. I had rocks curing for about a year in a brute container. Recently I filled the 40 up half way and put the cured rocks in there. Plus I also put some of the rocks from my sump in there as well. Thinking a combination would be best. They have all been sitting in the half full tank for about 4 weeks with a power head and a heater. Last night I noticed that the tank smelled bad. Why all of sudden? It just so happens that I’m ready to officially plum them together now that my lights have arrived for the second tank.

last night I filled it the rest of the way with water from my 90 and added carbon. Smells fine today. Is that good or should I be worried to combine systems?

 

[Jay Hemdal]

I’m starting a new 40gallon tank that I plan to plum into my main 90. I had rocks curing for about a year in a brute container. Recently I filled the 40 up half way and put the cured rocks in there. Plus I also put some of the rocks from my sump in there as well. Thinking a combination would be best. They have all been sitting in the half full tank for about 4 weeks with a power head and a heater. Last night I noticed that the tank smelled bad. Why all of sudden? It just so happens that I’m ready to officially plum them together now that my lights have arrived for the second tank.

last night I filled it the rest of the way with water from my 90 and added carbon. Smells fine today. Is that good or should I be worried to combine systems?

I've found that different people have different sensitivity to smells. Did this smell like rotten eggs? If I understand the chemistry correctly - this sounds like hydrogen sulfide. That forms by bacterial action in the absence of oxygen. The bacteria grows in the tight crevices of rock, especially when covered by water which lowers the available oxygen. Once exposed to oxygen, it eventually becomes oxidized to sulfate and the smell goes away. Hydrogen sulfide is pretty toxic to aquatic life, but it is transient.

Jay

 

[Heabel7]

I've found that different people have different sensitivity to smells. Did this smell like rotten eggs? If I understand the chemistry correctly - this sounds like hydrogen sulfide. That forms by bacterial action in the absence of oxygen. The bacteria grows in the tight crevices of rock, especially when covered by water which lowers the available oxygen. Once exposed to oxygen, it eventually becomes oxidized to sulfate and the smell goes away. Hydrogen sulfide is pretty toxic to aquatic life, but it is transient.

Jay

Kinda like rotten eggs. Same smell you get from a backed up sink.