Bubbles from substrate...

[bcarleton]

OK, I know something is not quite right with my tank but not sure what. All the typical tests come back fine (trate, trite, phos, etc.). But nothing looks happy. The tank has been developing an algae issue over the last few weeks. I thought maybe the T5 bulbs are getting old so have new ones due in tomorrow. The MH bulb is only about 3 months old. Last water change was 2 weeks ago. Watching the tank today I am noticing lots of tiny bubbles rising from the substrate. More than I Have seen before. I know I am going to get yelled at for this but as an FYI the bottom is crush coral, not sand or bare. I know better now, but when the tank was started I listened to someone who did not know squat. Could this bubble production be the issue of why all the corals do not look happy.

[DaveK]

You could be having some anaerobic bacteria deep in the sand bed. Crushed coral is an excellent dirt trap. How deep is you crushed coral?

Also algae problems are caused by not controlling nitrates and phosphates. Even if your test kits read 0, you can sill have a problem. It's quite possible for the algae to be absorbing the nutrients, and keeping the level low.

[DrHank]

Hopefully the rising bubbles are free nitrogen gas from the breakdown of Nitrate. The down side is that if this is happening in the substrate it is probably from the action of anaerobic bacteria. Also, a by product of this action is the production of Hydrogen Sulfide Gas. This is toxic to everything in your tank in very small amounts.

Have you noticed any change in the smell around the tank? As hydrogen sulfide is released, it gives off a rotten egg odor.

What ever you decide to do, I would avoid disturbing the substrate which could result in releasing the gas with devastating results.

[bcarleton]

Nope, no smell. Just smells like salt water. The bed is fairly deep, say about 2.5 tp 4.5 inches depending on exact spot.

[DrHank]

I'd just keep an eye on the situation and not disturb the substrate. Let your CUC do the job for you.

[bcarleton]

New bulbs have been in for 2 days and everything is looking much better. Algae is deminishing and bubbles from subst. is much less.

[jnohs]

I would recomend cutting back drasticaly on feeding. I feed maybe once every other week. and my fish are fat. in a reef tank there is only one place that nitrates,nitrites and what not can get in to your tank that is something dying and rotting or the food that you add.and that is it. so if nothing died and you stop feeding than after 2 weeks and 2 large water changes you will se a difference. Also make sure you are using ro water to do water changes. the temp should not go higher then 82 degrees.

[MountainFish]

so anaerobic bacteria is bad for your tank? I thought that was part of the natural process of breaking down trites and trates?

[sjsoto]

anaerobic bacteria is good for your tank to break up waste, but in the process it produces harmful gases that water changes are required, and cleaning sand bed is also a requirement... thats why its advice to stir sand bed to loosen up harmful traped gases before they accumulate.