Bottom dropped out of my pH

[vessxpress1]

Hey guys. I'm running a 20 gal frag tank and it's been up for a few months. I have two furnaces that draw fresh air in during the colder months. It got hot here in the last couple days so we've closed everything up and switched over to AC. At about the same time the bottom dropped out of my pH. I was doing great. I check it on the Apex app multiple times a day. Might have 8.25 during the day and drop down to 8.05 at night. I run 3 types of macro in the back of it under a grow light on a reverse cycle. Its doing nothing.

Now I can't even get the pH back to 8.0. I just did a water change and cleaned and recalibrated the 1 month old pH probe thinking maybe it's the probe. Now it's reading even lower. Says I'm sitting at 7.77 right now. It is not easy to try to get fresh air to where this thing is at so I'm just wondering if anybody knows how much the pH might jump if i can get a small line ran from a window to the skimmer intake? There's no opening windows in my basement. My hand held Hanna meter is giving me 7.95. If I just do a Salifert test I'd guess the color was giving me 8.2. So I don't know what to believe. The alk is at 9.1 on a hannah tester right now. It's hard to believe the pH could be this low. The probe on the apex reads exact in the calibration solutions.

What pH do i need to really start getting concerned at? What should I believe for a reading right now? This 7.77 during the day is making me cringe.

 

[Uncle99]

7.7 is fine,I mean PH tests are not that accurate so your 7.7 maybe 7.8, or 7.9.
I run fresh air to skimmer, get maybe .1 out of that, but it’s free and easy.
You could drip or dose Kalk if you want
I have never chased PH, there’s no value, PH runs between 7.8 and 8.3.
I have not tested PH now in years.

 

[William Mumford]

Co2 scubber I suggest a closed loop. Best 40 dollars I've spent.

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