Anyone monitoring aquarium CO2 (carbonic acid)?

[taricha]

@jccaclimber I think @Lasse has used a similar rig but without the bubbling. Just a large amount of tank water, small airspace above, and CO2 sensor in the small sealed airspace above the water. It'd be slow equilibrium, I think, but maybe Lasse can comment on how well it worked.

 

[Lasse]

@jccaclimber I think @Lasse has used a similar rig but without the bubbling. Just a large amount of tank water, small airspace above, and CO2 sensor in the small sealed airspace above the water. It'd be slow equilibrium, I think, but maybe Lasse can comment on how well it worked.

No - I did not do as good as that I have a CO2 sensor in my living room - I compared the measurements of that unit and my pH when my grandchildren woke up in the morning - there was a clear correlation. I can´t redo the measurements just now - they have not been here since March - you all know why

Sincerely Lasse

 

[Mateusz]

Does anyone believe that a high co2 level in the tank could cause corals to randomly die off with no explanation? I recently hooked up a co2 scrubber and I really think some of my corals look better than ever in my softie system. Sorry if i'm going off topic here at all.

 

[Randy Holmes-Farley]

Does anyone believe that a high co2 level in the tank could cause corals to randomly die off with no explanation? I recently hooked up a co2 scrubber and I really think some of my corals look better than ever in my softie system. Sorry if i'm going off topic here at all.

It can, but it would require very low pH to kill corals. I think it would require an accident, such as a CO2 cylinder stuck open.

 

[Mateusz]

It can, but it would require very low pH to kill corals. I think it would require an accident, such as a CO2 cylinder stuck open.

I see. My pH is stuck around 7.8 and I just can't seem to get it up... I have no idea how to measure co2 concentration in the water or anything though. I'm a simple peon compared to alot of you guys with this stuff.

 

[Randy Holmes-Farley]

I see. My pH is stuck around 7.8 and I just can't seem to get it up... I have no idea how to measure co2 concentration in the water or anything though. I'm a simple peon compared to alot of you guys with this stuff.

There's no need to measure Co2. It is exactly reflected by pH and alkalinity (knowing any two of those can give the third one mathematically). pH 7.8 is not leading to coral deaths. I would look for other explanations.

 

[Mateusz]

There's no need to measure Co2. It is exactly reflected by pH and alkalinity (knowing any two of those can give the third one mathematically). pH 7.8 is not leading to coral deaths. I would look for other explanations.

Looking into it, possibly ecobalance since thats the only other thing i've been adding. But nobody in gods creation will tell anyone whats in any of these bacterial products that are being sold. Could be cat pee and ammonia for all I know.

 

[Biologic]

There's no need to measure Co2. It is exactly reflected by pH and alkalinity (knowing any two of those can give the third one mathematically). pH 7.8 is not leading to coral deaths. I would look for other explanations.

I'm doing a complete blackout. Thick garbage bags. Not a shred of light coming in. Absolute dark. Did this last night around 11 PM.

Also last night, I'm running a limewood airstone, small tank, a JBJ 28 gal. The air pump is outside. Salinity is 34.5 ppt (Veegee Refractometer, calibrated). As you can see, my pH is actually a function of my dinoflagellate population lol. Alk is 7.7 dKH.

The airstone doesn't seem to be changing anything. Where in heck are the additional H+ ions coming in this system?

 

[Randy Holmes-Farley]

I'm doing a complete blackout. Thick garbage bags. Not a shred of light coming in. Absolute dark. Did this last night around 11 PM.

Also last night, I'm running a limewood airstone, small tank, a JBJ 28 gal. The air pump is outside. Salinity is 34.5 ppt (Veegee Refractometer, calibrated). As you can see, my pH is actually a function of my dinoflagellate population lol. Alk is 7.7 dKH.

The airstone doesn't seem to be changing anything. Where in heck are the additional H+ ions coming in this system?

I don't see a pH value, so it is hard to understand what you are suggesting, but nearly all organisms will be excreting CO2 in the dark, lowering pH.

 

[Biologic]

I don't see a pH value, so it is hard to understand what you are suggesting, but nearly all organisms will be excreting CO2 in the dark, lowering pH.

oops forgot the attachment, also, I have no skimmer on this tank. I am thinking about adding an airstone or microskimmer.

 

[Randy Holmes-Farley]

The entire period is blacked out?

There must ben enough light coming in for some photosynthesis. Remember, creatures photosynthesize pretty deep in the ocean where only a tiny fraction of sunlight penetrates.

 

[Biologic]

The entire period is blacked out?

There must ben enough light coming in for some photosynthesis. Remember, creatures photosynthesize pretty deep in the ocean where only a tiny fraction of sunlight penetrates.

No my apologies that graph isn’t clear. I was trying to show how my system is on a daily basis. As of last night at 11 PM I blacked out my aquarium. I was expecting a slight upturn from the morning low. Even without light.

 

[Randy Holmes-Farley]

OK, it will be interesting to see where it goes, but it is definitely not surprising if it is down relative to in the light.

 

[jccaclimber]

A little over-done, but I finally got around to making an adapter that doesn't require drilling any of my CO2 scrubber containers. I made an inline adapter for the canister, and here is how I ported in the PH probe.

Here is the air bubbling through. This is the second chamber of a CO2 scrubber which recirculates my skimmer air. The inlet is over the skimmer lid and the outlet goes into the skimmer air intake muffler. While I normally get condensation in the first chamber, I don't normally get any in the second chamber, so hopefully that will continue to be the case and the volume (and therefore alkalinity) will remain close enough to constant. As you can see from the first photo I also have soda lime inline in this system (why it exists to begin with). I figure I'll need to take out the media upstream of this chamber, but I'm not sure if I'll need to take out the downstream media. That will depend on how good the air exchange in the skimmer is. I'm planning to run it both ways and see if it makes any difference, assuming I see any meaningful data to begin with.

Right now I just have RO water in the container, but I'll have to make up some 4 dKH to replace the RO water, and I'll calibrate the pH probe while I'm at it. Randy, any recommendations for making up a batch of that using soda ash vs. sodium bicarbonate vs. kalkwasser? I have a cheap gram scale that does decently against a calibration weight set, but will probably need to use the same (500 g max, 0.01 g resolution, TBD accuracy) scale for my powder and liquid measurement. I can validate against my hobbyist alk kit and Trident, but are there any other good options?

I did put in accommodations for a couple other ports, so are there any other probes it would be useful to have in here? I can see temperature being useful for the pH probe as the room is cooler than the tank, but I'm not convinced it is going to make that much of a difference for the accuracy needed at this stage.