Can you "visualize" nitrogen gas bubbling from live rock or Marine Pure, after conversion by anaerobic bacteria in live rock or Marine Pure Blocks?

schooncw · Jan 1, 2022

Happy New Year!
Can you "see" nitrogen gas-bubbles-exiting live rock or Marine Pure blocks after the anaerobic bacteria has converted it? I am interested, only because someone is insisting this is so and I can find no link one way or another.
I think the "bubbles" he sees from the MP block in the sump is oxygen. That's where his skimmer is.
Thanks.

Garf · Jan 1, 2022

schooncw said:
Happy New Year!
Can you "see" nitrogen gas-bubbles-exiting live rock or Marine Pure blocks after the anaerobic bacteria has converted it? I am interested, only because someone is insisting this is so and I can find no link one way or another.
I think the "bubbles" he sees from the MP block in the sump is oxygen. That's where his skimmer is.
Thanks.

Yes, I can visualize it, but never experienced it. Theoretically sound, I suppose. I ran a DSB back in the day, never saw a denitrification that was measurable. Concluded it was irrelevant to aquaria. Would be pleased if I am wrong though

Edit - happy new year

schooncw · Jan 1, 2022

I have no doubt about denitrification from a DSB, bio pellets, large pieces of live rock, etc., I just want to know if one can visualize nitrogen gas "bubbles", as my associate puts it. He maintains that he can see nitrogen gas escaping from live rock and marine pure blocks and I think not.
I think any "bubbles" he sees in the MP in his sump is O2, as his skimmer is in the sump. As far as nitrogen bubbles escaping his live rock, I think not but ideally, the water should be saturated with O2, no?

Garf · Jan 1, 2022

schooncw said:
I have no doubt about denitrification from a DSB, bio pellets, large pieces of live rock, etc., I just want to know if one can visualize nitrogen gas "bubbles", as my associate puts it. He maintains that he can see nitrogen gas escaping from live rock and marine pure blocks and I think not.
I think any "bubbles" he sees in the MP in his sump is O2, as his skimmer is in the sump. As far as nitrogen bubbles escaping his live rock, I think not but ideally, the water should be saturated with O2, no?

If it’s lit, it would likely be photosynthetic by products. But like you say, micro bubbles could be joining forces.

taricha · Jan 2, 2022

I *think* it's very hard to observe N2 bubbles from denitrification.
Denitrification is going to be really slow.
The amounts of nitrate present are small (~10's of ppm), and the removal rate is low. The solubility of N2 gas is like maybe 1.5x that of O2.
Photosynthesis is booming all over a reef tank. Capable of generating several times the solubility of O2 across a system in a day.

schooncw said:
I think the "bubbles" he sees from the MP block in the sump is oxygen. That's where his skimmer is.

Reef systems have a lot of pumps and pipes that are capable of generating conditions where air mixes with water under slightly higher pressure than elsewhere in the tank. This will supersaturate the water with all the air gasses. Later those can form bubbles on surfaces.

N2 from denitrification just seems like the least likely candidate for an observed bubble on a block.

(now, if it's a carbon-fed reactor, those things could really accelerate the process - then maybe you can observe a some N2 bubbles.)