Weather/Temperature and its effects on pH and Alkalinity consumption?

smartwater101 · Jul 27, 2019

pH: normally ~8.49 - 8.55, now its ~8.35 - 8.45
(apex, re-calibration confirmed accurate. As accurate as apex can be anyway. Rabble Rabble)
Alk: normally ~9.2 - 9.5, now its ~9.6 - 9.9
(alkatronic, re-calibration confirmed accurate. Also confirmed with Hanna & Red Sea)

Neither is a big deal, this is just a curiosity. I noticed my pH falling and my alkalinity rising and i thought I'd read some posts about this in the past. The only change to the system is the local weather is getting HOT. Normally my chiller only turns on once a day and lately its been more like 5-6 times. I keep my temp within 77.8-78.8 so the changes aren't drastic but I'm really curious: Does Temperature even have much affect on ph and alk/cal consumption?

Hitman · Jul 27, 2019

Don’t recall where I read it, I think one of @Randy Holmes-Farley articles but I thought temp had a small effect on PH and I know PH has a effect on Alk and Ca consumption. Not sure if that really help answer your question or just added more to think about lol

Crabs McJones · Jul 27, 2019

Temp does have an effect on PH which in turn has an effect on alk consumption. The higher the PH the more alk consumed. I noticed a dramatic decrease in my alk consumption when we had to close all the windows and turn on the AC. My CO2 levels increased which decreased ph. My ph went from 8.3-8.5 down to 7.9- 8.0 and my dkh consumption dropped by almost a whole point per day. But temperature does have an effect on ph, the colder the water the more oxygen it can hold the more CO2 it can release increasing the ph (or at least that's my understanding of it). I believe apex even has a setting for temp compensation when calibrating a probe.

smartwater101 · Jul 27, 2019

Hitman said:
Not sure if that really help answer your question or just added more to think about lol

lol no worries. The correlation of ph/alk is something I'm aware of. I plan to slowly increase the alk to 10 eventually. I just didn't want it to happen over the course of 1 or 2 hot days. I'd rather do something like that over the course of a month or so. slow and steady

Randy Holmes-Farley · Jul 27, 2019

Biggest effect is going to be windows open vs closed. Wind outside and even temps outside impact air flow through the home.

b4tn · May 29, 2020

So bringing this one back. The last few days my alk consumption has started dropping. Over the past few days I have adjusted from using 38 ml of two part to 30. Since normally in the past a drop in consumption means problems I was concerned. I started racking my brain what has changed and it hit me. We have been having our first humid 80 degree days here and the AC has started kicking on. Out of curiosity I checked PH and sure enough it was down to 8.0 from the normal 8.3. Makes sense now. I have a window a few feet from the tank I may give it a small crack and see if that helps.

Randy Holmes-Farley · May 30, 2020

b4tn said:
So bringing this one back. The last few days my alk consumption has started dropping. Over the past few days I have adjusted from using 38 ml of two part to 30. Since normally in the past a drop in consumption means problems I was concerned. I started racking my brain what has changed and it hit me. We have been having our first humid 80 degree days here and the AC has started kicking on. Out of curiosity I checked PH and sure enough it was down to 8.0 from the normal 8.3. Makes sense now. I have a window a few feet from the tank I may give it a small crack and see if that helps.

It should help, if air is coming in through it.