The eggy waft.

While I was ill, I did little in the way of tank maintenance except for water changes.
Yesterday, I blitzed the tanks and moved the wood, giving them a thorough going over.
There must have been a bit of a build up in one tank – as my gravel farted and bubbled and I got the ‘eggy waft.’

I was just wondering, if you guys realise there’s been a build up – do you do anything extra? A larger water change? Add anything to the tank?

Cheers.

Hydrogen sulphide

Hi all,
MTS work fairly well in stopping the build up of hydrogen sulphide H2S (the "eggy" gas) by turning the gravel over, and plant roots are great as they act as both by creating physical channels in the gravel and also the plant roots pump oxygen into the rhizosphere (the zone around the growing root).

Other possibilities are substrate warming cable, these don't work the way they are meant to for plant growth, but do create convection currents in the gravel. If you can get very highly oxygenated water this will also controls substrate sulphide production, you can do this by using hydrogen peroxide generator (too risky for my taste), or a wet and dry trickle filter. These all work by reducing the redox potential of the substrate.

A final possibility is add some laterite or other iron rich clay (basically any brick red coloured clay (or possibly calcined clay?)) to your substrate, the iron oxides in the laterite react with sulphides present to create insoluble iron sulphide.

I use quite thick sand substrate, with a small amount of leaf mould, clay and calcined clay ("Seramis"), lots of plants and MTS, and I don't ever vacuum the sand, but the sand doesn't smell when I break a tank down, I don't know if the clay/seramis would be enough on their own (although I'm sure the plants/MTS would).

I've got this paper if anyone wants a copy?

Ori Lahav, Gad Ritvo, Iris Slijper, Giovanni Hearne, Malka Cochva
"The potential of using iron-oxide-rich soils for minimizing the detrimental effects of H2S in freshwater aquaculture systems"
Aquaculture, Volume 238, Issues 1-4, 1 September 2004, Pages 263-281

cheers Darrel

I use sand rather than gravel, and turn it over every few weeks, as well as being overrun with MTS (not just Multiple tank syndome , but malaysian Trumpet snails).
With sand I can use a holey net (eg green rather than the blue or white tighter nets) and sift the sand and remove excess snails and turn it about. I only do one end of the tank at a time.
Anyway glad to here you are on the mend now!