What exact level IS high CO2 in a house?

[jmaneyapanda]

I have a 50 gallon mixed reef with a moderate to moderate high fish load, good skimming 24 x 7, a constant airstone running in the sump, kalkwasser drip, small refugium, and its open top. I dose Fusion 1, Fusion 2, and magnesium. Alk usually upper end of ok at 9-10.5, calcium 410-445, magnesium 1250-1350. My pH is sporadically lower than I hope for (7.75 to 8.0 daily). I have tried a co2 scrubber, and am currently drawing outside air to my skimmer. None of these things seem to boost pH much at all. The highest I've ever seen it is 8.2. I see this is mostly caused by elevated room/house CO2, hence the co2 scrubber and outside air draw efforts.

I have a room sensor that read CO2 as well as recently adding the AvidAqua Insight screen which also measures room CO2. What CO2 level is exactly cnsidered "high" CO2? The sensors have estimations of what is "good", "bad", etc. I have a lot of pets, but also a ton of plants in my house, and my Co2 sensors consistantly read in the "good" area, going between 400 and 500 ppm. The highest I ever saw it was 900 after my HVAC was turned off for a while. This is corroborated between two unrelated devices reading this.

Would a household CO2 of 450 on avergae depress tank pH that much? What am I missing?

 

[Uncle99]

I have a 50 gallon mixed reef with a moderate to moderate high fish load, good skimming 24 x 7, a constant airstone running in the sump, kalkwasser drip, small refugium, and its open top. I dose Fusion 1, Fusion 2, and magnesium. Alk usually upper end of ok at 9-10.5, calcium 410-445, magnesium 1250-1350. My pH is sporadically lower than I hope for (7.75 to 8.0 daily). I have tried a co2 scrubber, and am currently drawing outside air to my skimmer. None of these things seem to boost pH much at all. The highest ive ever seen it is 8.2. I see this is mostly caused by elevated room/house CO2, hence the co2 scrubber and outside air draw efforts.

I have a room sensor that read CO2 as well as recently adding the AvidAqua Insight screen which also measures room CO2. What CO2 level is exactly cnsidered "high" CO2? The sensors have estimations of what is "good", "bad", etc. I have a lot of pets, but also a ton of plants in my house, and my Co2 sensors consistantly read in the "good area, going between 400 and 500 ppm. The highest I ever saw it was 900 after my HVAC was turned off for a while. This is corroborated between two unrelted devices reading this.

Would a household CO2 of 450 on avergae depress tank pH that much? What am I missing?

500 to 800 normal average.
North of 1000 starts to be elevated.

So your reading of 450ppm would not be a contributor to depressed PH.

Your PH is fine, if we assume it’s actually correct.

PH is one of the hardest things to consistently measure and many times sends the reef keeper
Into a “Wild goose chase” for no value.

You’ve done all the things to maximize PH. Just keep that stuff going.

Never a need to measure it again IMM.

Fell into that trap 2 decades ago. Have not measured PH in 20 years now.

 

[exnisstech]

If you want to make sure it is or isn't indoor co2 you can perform an aeration test.

The Aeration Test

Some of the possible causes of low pH listed above require an effort to diagnose. Problems 3 and 4 are quite common, and here is a way to distinguish them. Remove a cup of tank water and measure its pH. Then aerate it for an hour with an airstone using outside air. Its pH should rise if it is unusually low for the measured alkalinity (Figure 2). Then repeat the same experiment on a new cup of water using inside air. If its pH also rises, then the aquarium’s pH will rise simply with more aeration because it is only the aquarium that contains excess carbon dioxide. If the pH does not rise in the cup (or rises very little) when aerating with indoor air, then that air likely contains excess CO2, and more aeration with that same air will not solve the low pH problem (although aeration with fresher air should). Be careful implementing this test if the outside aeration test results in a large temperature change (more than 5°C or 10°F), because such changes alone impact pH measurements.


The full article

 

[jmaneyapanda]

500 to 800 normal average.
North of 1000 starts to be elevated.

So your reading of 450ppm would not be a contributor to depressed PH.

Your PH is fine, if we assume it’s actually correct.

PH is one of the hardest things to consistently measure and many times sends the reef keeper
Into a “Wild goose chase” for no value.

You’ve done all the things to maximize PH. Just keep that stuff going.

Never a need to measure it again IMM.

Fell into that trap 2 decades ago. Have not measured PH in 20 years now.

Its just on my Apex. I recently added a new, calibrated probe, and it read darn near exactly what the old one was. But piont taken.

 

[jmaneyapanda]

If you want to make sure it is or isn't indoor co2 you can perform an aeration test.

The Aeration Test

Some of the possible causes of low pH listed above require an effort to diagnose. Problems 3 and 4 are quite common, and here is a way to distinguish them. Remove a cup of tank water and measure its pH. Then aerate it for an hour with an airstone using outside air. Its pH should rise if it is unusually low for the measured alkalinity (Figure 2). Then repeat the same experiment on a new cup of water using inside air. If its pH also rises, then the aquarium’s pH will rise simply with more aeration because it is only the aquarium that contains excess carbon dioxide. If the pH does not rise in the cup (or rises very little) when aerating with indoor air, then that air likely contains excess CO2, and more aeration with that same air will not solve the low pH problem (although aeration with fresher air should). Be careful implementing this test if the outside aeration test results in a large temperature change (more than 5°C or 10°F), because such changes alone impact pH measurements.


The full article

I can certainly do this. However, if I find that the pH does rise in my outside tested sample, what can I do that's actionable? I dont think theres much more I can do inside my home to decrease co2 where the aquarium is.

I just find it hard to believe this is CO2 related.

 

[Uncle99]

Its just on my Apex. I recently added a new, calibrated probe, and it read darn near exactly what the old one was. But piont taken.

Me too but mines sits on the shelf because as time passed, I never knew if variances were probe fluxes or normal room fluxes and I just got lost in that.

The probe would seem to drift and required a ton of calibration so just got annoying.

 

[exnisstech]

I can certainly do this. However, if I find that the pH does rise in my outside tested sample, what can I do that's actionable? I dont think theres much more I can do inside my home to decrease co2 where the aquarium is.

I just find it hard to believe this is CO2 related.

No help here. I got a nice bump with a outside airline to the skimmer.

Maybe take a look at this thread and see if any of the info is helpful.

https://www.reef2reef.com/threads/m...-outdoor-aeration-ph-boost-stability.1084802/

 

[Kooma]

I see a major bump when our house air exchanger is running on low 24/7. Lows of 8.2 and highs of 8.4. I have a 250 gal long and a regal 250 INT skimmer, closed glass lid.

Could increase aeration of the tank, that may help you. I can say my skimmer upgrade took me from 8.2 highs to 8.4.

 

[Randy Holmes-Farley Verified Community Expert]

I can certainly do this. However, if I find that the pH does rise in my outside tested sample, what can I do that's actionable? I dont think theres much more I can do inside my home to decrease co2 where the aquarium is.

I just find it hard to believe this is CO2 related.

Bring in fresher air to the skimmer or the whole room.

It’s a way to distinguish high ambient CO2 from inadequate aeration using the existing air.

 

[jmaneyapanda]

I can certainly do this. However, if I find that the pH does rise in my outside tested sample, what can I do that's actionable? I dont think theres much more I can do inside my home to decrease co2 where the aquarium is.

I just find it hard to believe this is CO2 related.

No help here. I got a nice bump with a outside airline to the skimmer.

Maybe take a look at this thread and see if any of the info is helpful.

https://www.reef2reef.com/threads/m...-outdoor-aeration-ph-boost-stability.1084802/

I’m already doing that. I guess I’m at where I’m at

 

[jmaneyapanda]

I see a major bump when our house air exchanger is running on low 24/7. Lows of 8.2 and highs of 8.4. I have a 250 gal long and a regal 250 INT skimmer, closed glass lid.

Could increase aeration of the tank, that may help you. I can say my skimmer upgrade took me from 8.2 highs to 8.4.

I run 2 mp40s in the tank, it’s open top, skimmer on 24/7, and an air pump in the sump. I don’t think I can aerate more.

 

[jmaneyapanda]

I can certainly do this. However, if I find that the pH does rise in my outside tested sample, what can I do that's actionable? I dont think theres much more I can do inside my home to decrease co2 where the aquarium is.

I just find it hard to believe this is CO2 related.

Bring in fresher air to the skimmer or the whole room.

It’s a way to distinguish high ambient CO2 from inadequate aeration using the existing air.

I already pull outside air in for the skimmer, and the co2 in the cabinet right now is 448 ppm and 403 ppm outside the cabinet (as of right now). I’m not sure how I can make an actionable difference on that.

Again, if I’m stuck where I am, so be it. I just wanted to make sure I’m not missing anything.

 

[Randy Holmes-Farley Verified Community Expert]

I run 2 mp40s in the tank, it’s open top, skimmer on 24/7, and an air pump in the sump. I don’t think I can aerate more.

Folks often say that, but if aeration was perfect, pH would not change day to night.

 

[Randy Holmes-Farley Verified Community Expert]

I already pull outside air in for the skimmer, and the co2 in the cabinet right now is 448 ppm and 403 ppm outside the cabinet (as of right now). I’m not sure how I can make an actionable difference on that.

Again, if I’m stuck where I am, so be it. I just wanted to make sure I’m not missing anything.

That difference is too small to be important. A doubling of CO2 causes about a 0.3 pH unit difference in perfectly aerated water.

 

[jmaneyapanda]

I run 2 mp40s in the tank, it’s open top, skimmer on 24/7, and an air pump in the sump. I don’t think I can aerate more.

Folks often say that, but if aeration was perfect, pH would not change day to night.

Yes I understand that (photosynthesis aside), but I literally can’t figure how to aerate more. Mechanically.

 

[jmaneyapanda]

I already pull outside air in for the skimmer, and the co2 in the cabinet right now is 448 ppm and 403 ppm outside the cabinet (as of right now). I’m not sure how I can make an actionable difference on that.

Again, if I’m stuck where I am, so be it. I just wanted to make sure I’m not missing anything.

That difference is too small to be important. A doubling of CO2 causes about a 0.3 pH unit difference in perfectly aerated water.

I don’t think I’m making my position clear. You suggested I allow fresh air into the room and skimmer. My skimmer already pulls outside (fresh) air, and my inside co2 at 400 ish (at worst) wouldn’t be considered “fresh”? I don’t see how opening my door would make co2 lower.

 

[Randy Holmes-Farley Verified Community Expert]

I don’t think I’m making my position clear. You suggested I allow fresh air into the room and skimmer. My skimmer already pulls outside (fresh) air, and my inside co2 at 400 ish (at worst) wouldn’t be considered “fresh”? I don’t see how opening my door would make co2 lower.

Yes, 400-450 is adequately fresh, IMO.

 

[Slack Tide Reef]

Are you letting the CO2 sensors calibrate with outside air occasionally?

 

[jmaneyapanda]

Are you letting the CO2 sensors calibrate with outside air occasionally?

On the Insight, yes. There is no calibration for my other standalone unit. But they read comparably.