Ammonia!

[newfishaddict]

Recently I had a conversation with my cousin, he has kept many salt and fresh water tanks in the past 10-15 yrs. He said that circulation at substrate level is very important, and that “pockets” high in ammonia/anaerobic bacteria reside at the substrate/water interface, and within the substrate. Is this true? How much of a concern is it? And how can it be prevented?

I assume a clean substrate affects this greatly…

I also suspect that circulation in some areas of my tanks are very limited.

My cousin said use air stones…is this the best plan? Or is it even required?

Anyone use airstsones under-substrate? I have read/heard that your substrate going anaerobic is very bad...?

 

[Teelie]

This is true only in substrate around 1.5-2" or deeper. Air stones won't help at all, they'll only cause surface ripples which will aerate the water nearer the top with the oxygen making its way down to the bottom in lower amounts.

Simple solution to this is to keep the substrate below 1.5" and stir it every month or so. It's not a real threat to most people if they keep their substrate clean.

 

[EliteFishy]

Will trumpet snails help?

 

[Teelie]

Yes but you'll still want to do the occasional sifting and cleaning of the substrate.

 

[Torrean]

Wouldn't an airstone beneath the substrate disturb the water around the gravel above it anough for oxygenated water to pass through the crevices? Also wouldn't the air moving through the substrate "clean" or flush out any anaerobic poisons. I'll admit it doesn't make much sense to cover your tank bottom with airstones and then cover them with gravel but if you did i think it would prevent anaerobic bacteria from colonizing the substrate.

 

[Teelie]

It might solve the anaerboic bacteria to an extent and allow water to pass through some of the crevices but as you said, it wouldn't make sense to cover the entire substrate with them and too many airstones can be a bad thing too. Fish can die from over oxygenation or from airbubbles catching in their gills.

You'll get colonization no matter what you do, it's the extent of the colonzation and the amount of gas allowed to build up that becomes an issue. The simpler solution is simply stirring the substrate up and keep it from being too deep, unless you have burrowers, diggers, plants and sifters like MTS'. I forgot that plant roots can help as they'll out compete the bacteria for some of the nutrients and help keep the substrate from compacting enough to allow them to grow.