Substrate producing sulfur.....2 fish dead.

redchigh

All my fish have been swimming at the surface for a while... I increased aeration slightly, and waited them to recover to no avail.

I tested the water, all the parameters were good. I gravel vac'd the substrate, and bubbles began rising from the substrate. Enough bubbles to nearly kill the siphon in the vacuum.
Also, I noticed the unmistakable odor of rotten eggs.

I did a 30% w/c and gravel vac'd everything I could reach, and the fish seem to be doing better...
How do I keep this from happening again?
How often should I gravel-vac?

The tank is planted, and has between 1.5-2 inches of gravel...

Also have a lot of MTS, so I sould have thought they would keep the gravel turned...

Byron

That's bad news. I'm wondering if there is something that may not be obvious yet. I have 4-6 inch gravel substrates and have never had this occur. I don't vacuum the gravel where the plants are, only along the open areas in front (due to the corys), so about 85% of my substrate is never touched, and that is common with many planted tank aquarists.

The plant roots if healthy produce oxygen for the aerobic bacteria. While there will naturally be areas of anaerobic bacteria in any substrate, they are natural and provided they don't increase cause no harm. They serve a process in the biological balance of the aquarium.

Are plants (substrate rooted) growing in these spots, or was it plant-less? And what grain size is the gravel?

Byron.

redchigh

The gravel is just typical gravel, probably 4-6mm if I had to guess.

The worst spot was relatively close to my dwarf sag. I'm not really sure if it's everywhere or just the front unplanted part since that's the only part I vac'd.

I plan on gravel vac'ing regularly until I figure out the cause... (I hadn't vac'd in a long time)

Mikaila31

IMO it is cause my excessive waste build up. I have the sulfur bubbles in my 55gal, but I've never noticed any effect on the fish. The bubbles are a issue around and under the log my 2 caecilians use as their burrow. Their is not a lot of plants around it and I know it is a high waste area. I vacuum this place regularly, but not the rest of the tank.

willow

hi
you could always get a long bamboo stick or fork tied to a stick and stir the gravel around
inbetween water changes,that's what i do.it gets into places the vac can't.
vac on a regular basis and you'll find you problem will lessen.