Sand bed producing bubbles

[Ewatson249]

My sand bed is producing quite a lot of air bubbles. They are not settling on it but they are coming from underneath as you can see it on the glass. My sand bed is about 2.5" maybe 3" in some places. Could this be the result of nitrates being broken down in the low oxygen area of the sand bed? I'm sure I read somewhere that the bacteria does it by separating the nitrate atom from the oxygen ones? Am I speaking total rubbish.... I have noticed that my nitrates have gone down from 5 to 0ppm over the last 2 days for the first time. Anyone got any ideas?

[bavass]

could be denitrafication. the bubbles are not in algae are they? if the bubbles are being released and floating to the top thats what you want

[Deep Seven]

Sounds like it. The nitrates can be broken down to nitrogen gas in anerobic conditions. If you're planning on corals or other nitrate sensitive animals then this is a good thing.

If you smell rotten eggs then it's a real concern.

[Ewatson249]

No there is no algae or smell of rotten eggs so things are looking up. In fact things seem to be going too well with this tank. I'm anxiously awaiting the come down!

[CaptainAhab]

or air trapped in the sand bed working it's way out. How old is the tank?

[Ewatson249]

Well it's not very old but this is a lot of air bubbles that I have not seen before. The sand has always looked quite compacted with no gaps in it. They are also quite uniform throughout the sand where as if it was trapped air you may expect it to only be in certain areas. How does everyone else maintain 0 nitrates? I used to keep freshwater and the thought of having no nitrates is brilliant!