anyone notice a pH decrease since the warm humid weather??

[jlinzmaier]

My pH had been rock solid for overy 6 months running around 8.25 during the day and around 8.05 during the night. I run my skimmer air intake outside for fresh air (to prevent indoor co2 from lowering pH of the water). Since the weather has been so hot and humid for the last week I've noticed my pH runs around 7.75 at night and 7.9-8.0 during the day (even after calibration of the probe). I don't know if there is a correlation or with the weather or if there is some other reason my pH is low. Anyone else notice a recent dip in pH??

Jeremy

 

[Viva'sReef]

I noticed this myself the other day.....I was going to do a calibration tonight to see if that was the issue. I'm getting nearly the exact same numbers as you now

 

[Sea MunnKey]

Funny .. this was the same questionnaire on my local forum as well ..

Paul

 

[condiman]

I notice that as well with mine.

 

[kass03]

I rarely test mine so did'nt notice. Ive never had PH issues mine is always around 8.3
I thought I read it lowers in the winter cuz the house is all closed up. Maybe with the AC running/ house closed it has something to do with it.

kass

 

[jlinzmaier]

OK well it's nice not to be the only one with some odd readings. LOL!! After I posted the question I thought it out a bit further and think I have a logical answer. Kass hit it right on I suspect!!

I run my skimmer air intake out my basement window becuase my house co2 level is generally high (the indoor co2 was lowering the pH of my water). When the weather got really hot we closed all the windows and ran the AC (house is very new and air tight). That likely further elevated the indoor co2 which in turn had a larger effect on the pH of the tank since there is such a large air/water surface area for the co2 to dissolve into the water. I'm sure if I didn't run my skimmer air intake out the window I would likely have much lower readings. If we get some cooler days I'll turn the AC off and open some windows in the basement and see if that in turn increases pH. If it does, then I guess that solidifies the theory that it's related to indoor co2.

Any other theories or suggestions are very much welcomed.

Jeremy

 

[siropa]

I'd recommend maybe using some kalk for top off during the summer, but I suspect what you'd say about using that

I don't test my pH enough to know what it is, but i've found in the past that with the air exchanger we have, co2 levels haven't been an issue.

plus the co2 of the outside air might be higher than it was in the past and you won't get the tank levels below what the general atmosphere levels are anyways.

 

[jlinzmaier]

Yeah, can't do kalk with zeo. Nearly all the zeo users I've spoken to coincidently have a low pH in general and it doesn't seem to affect growth rates. I've argued the whole calcification in regards to pH levels until I was blue in the face, but I can't argue with their clear cut experiences of running a pH of 7.5-7.7 and having growth rates through the roof.

I wonder if the atmospheric co2 is higher on these hot muggy days or if it is just related to having the house more closed up?? I don't plan on turning off my AC and opening the windows on a day like this just to test that out. I'll do some research about atmospheric co2 and see if I can find info about how it changes (if at all) with the temp or humidity.

Jeremy

 

[kass03]

Yeah Jeremy that was the reason I read about that it lowers in the winter. The co2 and especially with newer air tight houses.

kass

 

[jlinzmaier]

After disucssion with some chemists, and a bit of research, the environmental co2 doesn't change with temp or humidity. Increases in environmental co2 can occur in low valleys and areas with lots of smog but that's obviously not a problem here in Wisconsin. This further encourages the theory that the drop in pH is related to an increase in indoor co2.

Thanks everyone.

Jeremy

 

[jlinzmaier]

Here's a bit more info from Boomer on RC. His response indicates that co2 levels are affected by relative humidity which will in turn affect a tanks pH. This is after several other commented that co2 levels are not affected by humidity or temp. I trust Boomer more than anyone in regards to this kind of stuff and his logic sounds quite legitimate.

Are the atmospheric co2 levels affected at all by the temp or humidity outside??

Yes they are for a number of reasons. First, CO2 monitors have RH coefficients build in to correct for RH, as it affect the CO2 reading. Second warmer air holds more water than colder air, where such water can absorb more CO2, where that water vapor is getting in the tank lowering the pH due to high CO2. This CO2 adsorbed by the water vapor also reduces the RH as the vapor falls to the ground/tank. Colder air or water also holds more CO2 than warmer air or warmer water.

Maybe the indoor co2 is now so concentrated that the skimmer simply can't negate as much of the co2 that is being dissolved through the air/water interface.

Yes, that could be the issue. Look at it this way from another perspective. A FW tank over loaded with fish will drive the CO2 up very high and lower the pH. The water never comes into equilibrium with the atm CO2 as it is being generated faster than it can leave the tank by diffusion. Adding a skimmer or air exchanger device can negate this if the exchange is fast enough. But then you have to throw in the skew that Tod gave, which was excellent but which negates your issue of lower pH. Lastly, other things that can affect things are the temp of the skimmer water, which is usually warmer than tank water, thus less CO2 exchange.

I do not know for sure Jeremy what you issue is but it is for sure, if it is happening, a gas exchange issue and may be a higher RH, which is higher in summer than winter. And I have no clue how much effect this would have on a tanks pH.

Jeremy

 

[Ernie C]

I know this is a very old post but I've noticed the same thing. We've had rainy weather for a week and my ph has been dismal when i usually have a nice 8-8.3 range. Since the rainy week started, i've been at 7.8-8.1 I run my air intake from outside, hourly kalk and CO2 scrubber. It seems to be a recurring trend and the only obvious variable is the weather outside being hot and humid and rainy. Not anything to worry about but I honestly think its weather related.