Skimmer=negative effect on ph?

[JDJP]

350 gallon sps system, large tumbling well lit(24/7) chaeto ball, very efficient skimmer, and pretty heavy calcium hydroxide supplementation. Tank is in a not well sealed to outside air room of the house. Could my skimmer be suppressing my ph?
This last week I went from averaging 8.1-8.3 to trending up to 8.2-8.4 . Last night I noticed my skimmer was off so I turned it back on and my ph dropped to 8.1 overnight. Is my skimmer contributing more CO2 to the system than its helping remove?
I can't find any info on anyone doing it, but I now have my skimmer air recirculating to see if my ph starts trending back up. I know my ph is fine either way, but I want to keep it higher.

dkh 8.5
Cal 450
Mag 1470
No3 5
Po4 .04
K. 450

 

[HuduVudu]

@JDJP first thing you need to know is what is your ambient CO2 level. Just because a house isn't well sealed doesn't mean that enough fresh air is getting in. I had a 1950's house that would get well over 2800ppm of CO2 and I finally stopped the experiment after a day and a half because this is dangerous.

Make the investment into a CO2 meter. Best investment you will ever make even if it turns out to not be an issue.

My 2 cents.

 

[Potatohead]

If the air has more CO2 than the water, yes it could be.

 

[SPS2020]

Have not purchased one yet, but these got good reviews.

CO2 Sensor

 

[Randy Holmes-Farley Verified Community Expert]

Skimmers aerate the water.

Aeration of any kind can raise or lower the pH depending on whether the tank water effectively has more or less CO2 in it than the air.

Aeration can even drive pH in different directions at different times of the day (for example, down during the day when tank CO2 is low and up at night when tank CO2 is high) and can also change direction or magnitude as the room CO2 changes with people present, cooking with gas, open windows, etc.