black spots and hydrogen sulfide during cycling

[aijeric]

Should I be concerned about black spots appearing on the bottom of the rock that's touching the sand and reeking of hydrogen sulfide?

[Geoff]

Welcome to TRT!!


black spots can be a few things. if the black spots are above the sand level, then i do not think that it is hydrogen sulfide. it may be Iron though. what kind of water did you use when filling the tank?

how long has the tank been running?

G~

[aijeric]

Thanks!

I just used dechlorinated tap water and the black spots do smell like rotten eggs. It's been over a week now since I started the cycle. I did a 90% WC and I just redid my aquascape yesterday so now it doesn't have any big dead spaces. Water tests with API kit are: ammonia: 1.0, nitrite: 5.0+(had a deep purple color), nitrate: 60ish

[Geoff]

it sounds like you really need to increase the amount of flow in the system. can you tell us a little about your system?

G~

[aijeric]

I have a rectangular 10G with about 2.5in of Ocean Direct oolithic sandbed. The water pump, hydor koralia 450, is in the middle of the longest glass pane, near the water surface and the live rocks are tightly touching each other and lined up in the middle with no stacking, while leaving open sand space around them. There's a "mountain" rock on each end, and flat rocks in the middle to allow the water flow to pass through with minimal effort. I followed the water flow, via the floating debris. It goes around the rocks and if it hits the glass, the topmost water goes downward then gets picked up by the water current from above, goes topward, then redo the cycle. It looks more complicated but it's just a simplified description.

This is the after the redo of the aquascape. Before I had both ends just get piled up nicely. The koralia is in the same spot. This left the rocks at the end of the water flow with greatly reduced water flow. Never smelled or saw black spots with the rocks in the area with the most water flow