Air bubbles with fish/corals - Science?

[zomb]

So I've done a lot of forum searching and reading about air stones and whether you should use them in a salt water tank with both fish and corals. Though I haven't found any actual good information or even real examples of what potentially bad things could result from it. Much of what I saw was that the bubbles could damage corals, possibly hurt fish. Some even suggested it could do the opposite and introduce more CO2 than oxygen.

Does anyone have any good data, whether it be from some sort of expert or actual personal experience of negative draw backs? ( I know salt creep will happen, I am okay with this ) I was thinking of putting one in the display and one in the sump, any suggestion as to do one or the other or both?

The reasoning for wanting to use the air stones is because I had a total fish wipe out almost 2 months ago and everything pointed to the fish dying of lack of oxygen ( If interested about the details check out http://www.reefcentral.com/forums/showthread.php?t=2679875 )

The tank has remained running the entire time and has not had any drastic parameter changes, only thing I had to do was offset the alk a little which is now about 9.8 dkh with a ph reading ~8.2 ( From my understanding CO2 will change ph )

The alternative to these I've read is just simply moving your powerhead up to disrupt the surface of the water. Would this be enough?

 

[Member No. 1]

Are you running a skimmer? This along with some surface agitation should be more than enough for gas exchange.
Yes, increased Co2 in the air will lower the pH. This is why some have tried to plumb the air intake for the skimmer to an outside source.

For what it's worth, NOAA has stated that Co2 is trending above 400 ppm. https://www.esrl.noaa.gov/gmd/ccgg/trends/
I have a Co2 meter as part of my PWS (Personal Weather Station) and with the windows open, my house runs about 450 ppm. If the windows are closed due to summer(AC), it get as high as 1,100 ppm. My pH runs daily from 7.85-8.15. I can tell by the tank pH when my house Co2 Levels are up by a lower pH reading. If I have company, the house Co2 level spikes.

There is a bunch of threads about people running an air stone at night in the return section of their sump to flood the tank with tiny micro bubbles. This has more to do with the scrubbing action the bubbles have on the rock. I have read, and I haven't heard anyone stating that this is harmful to corals or fish. So far only good reports.
Will this increase the O2 content of your water, I highly doubt it as long as you have a skimmer running and good surface agitation.

Unless when your fish died, you checked the O2 content of the water, I would look for another reason for the die off. What first comes to mind is an ammonia spike.

 

[zomb]

Are you running a skimmer? This along with some surface agitation should be more than enough for gas exchange.
Yes, increased Co2 in the air will lower the pH. This is why some have tried to plumb the air intake for the skimmer to an outside source.

For what it's worth, NOAA has stated that Co2 is trending above 400 ppm. https://www.esrl.noaa.gov/gmd/ccgg/trends/
I have a Co2 meter as part of my PWS (Personal Weather Station) and with the windows open, my house runs about 450 ppm. If the windows are closed due to summer(AC), it get as high as 1,100 ppm. My pH runs daily from 7.85-8.15. I can tell by the tank pH when my house Co2 Levels are up by a lower pH reading. If I have company, the house Co2 level spikes.

There is a bunch of threads about people running an air stone at night in the return section of their sump to flood the tank with tiny micro bubbles. This has more to do with the scrubbing action the bubbles have on the rock. I have read, and I haven't heard anyone stating that this is harmful to corals or fish. So far only good reports.
Will this increase the O2 content of your water, I highly doubt it as long as you have a skimmer running and good surface agitation.

Unless when your fish died, you checked the O2 content of the water, I would look for another reason for the die off. What first comes to mind is an ammonia spike.

That was actually a lot of very helpful information, thank you. I do run a skimmer and it was during one of the hottest streak we had so windows weren't ever open. It was likely there was higher CO2 in the air. I didn't think of having something to record the CO2 in the air, I will look into that. I also do not have a way of testing O2 in the water, what do you use to do that?

I tested every possible parameter after the death. The ammonia was 0. I had cleaned some algae off the tank using a magnet cleaner, a lot of the algae had bubbles all over it. Shortly after fish by fish dropped to the bottom gasping for air and within 30 minutes every single fish died. The corals and clam had all closed up like they do when sleeping and within an hour the corals started opening back up again. I'm pretty certain it was lack of oxygen that caused the deaths and just want to do everything I can to avoid that. However, you do bring a good point, if CO2 is high then all I would be doing is pumping higher CO2 to O2 ratio into the tank and likely it isn't necessary since the skimmer is doing that anyways. It also makes sense because when this happened ( I live in CO ) a lot of the state was on fire and I'm sure that meant CO2 levels were higher than other parts of the country.

Possibly, I just need to adjust my powerheads to hit the side of the tank to prevent build up of bubbles. Thank you again for the info.

 

[Member No. 1]

That was actually a lot of very helpful information, thank you. I do run a skimmer and it was during one of the hottest streak we had so windows weren't ever open. It was likely there was higher CO2 in the air. I didn't think of having something to record the CO2 in the air, I will look into that. I also do not have a way of testing O2 in the water, what do you use to do that?

I tested every possible parameter after the death. The ammonia was 0. I had cleaned some algae off the tank using a magnet cleaner, a lot of the algae had bubbles all over it. Shortly after fish by fish dropped to the bottom gasping for air and within 30 minutes every single fish died. The corals and clam had all closed up like they do when sleeping and within an hour the corals started opening back up again. I'm pretty certain it was lack of oxygen that caused the deaths and just want to do everything I can to avoid that. However, you do bring a good point, if CO2 is high then all I would be doing is pumping higher CO2 to O2 ratio into the tank and likely it isn't necessary since the skimmer is doing that anyways. It also makes sense because when this happened ( I live in CO ) a lot of the state was on fire and I'm sure that meant CO2 levels were higher than other parts of the country.

Possibly, I just need to adjust my powerheads to hit the side of the tank to prevent build up of bubbles. Thank you again for the info.

This is the PWS that I have. I can log on to it from any place that I have an internet connection. Either thru the app, or a web browser. https://www.netatmo.com/en-US/product/weather/weatherstation

I do not have any way to measure water O2 levels. They do sell them, but they are super expensive.
Probe is $700 then you need the module at $100. https://www.bulkreefsupply.com/lab-grade-dissolved-oxygen-probe-neptune-systems.html There might be others, but I never looked because you just don't need one.

If the algae had bubbles that were released when you scrapped it, and since plants produce O2 and take in Co2, during photosynthesis, then by that reasoning you would have added 02 to the tank.
Another possibility is if you disturbed the sand bed, or there was a lot of decaying organic matter, there could have been a release of Hydrogen Sulfide. H2S is highly toxic and extremely poisonous.
It smells like rotting eggs, or to put it another way, the smell of low tide!
https://www.google.com/search?ei=3h...k1j0i10i67k1j0i131i67k1j0i3k1.171.7NV7tr7O4a0