Planted Tank Guru
Join Date: Nov 2009
Location: Missouri united states
You need more plant's,a lot more.
Plant's can transport oxygen to their root's and no worries bout hydrogen sulphide.
Your substrate depth is not deep enough for the H2s boogey man to even be concern.
Trumpet snail's too make H2s non issue.
Is more likely oxygen escaping.
Honestly,, maybe five out of a hundred people could say they have smelt real rotten egg's.
Hydrogen sulphide is rendered harmless once it makes contact with oxygen in the water.
If this were not so,,then those running deep sand bed's in marine tank's would report all kind's of issues and they don't.
Foul smelling tanks ,particularly those that smell of ammonia are often result of dirty filter's where organic matter collect's and begins to decay.