PH Swings?

[d2mini]

Any idea what might be causing my PH swings? And I'm not talking about night vs day, but day to day swings. Like one day my ph might be 7.86 and another day it's 8.4. Via my ReefKeeper Lite.
I dose brs two part, using the soda ash to keep my ph up but i'm using brs dosers so that should be pretty consistent. Skimmer runs constantly. My water changes are automatic, little bits throughout the day, every day. Rimless, open top so plenty of consistent gas exchange. And i have a shop light over the fuge at night. I can't think of anything else. Ideas?

 

[little_fish]

When was the last time you calibrated your pH meter? I know several of the meters often need to be calibrated.

 

[d2mini]

A few months ago.
I could see if it was consistently low or consistently high.
But I don't think the large swings would be from needing to be calibrated?

 

[fastrd400]

Mine does the same thing Dennis. I was told by someone that it could be due to some electrcal interference. Though I am using a Pinpoint pH monitor and not a RK.

 

[yote]

If I'm thinking right,your RKL is right at a year old,maybe a little older?
Their probes usually just last about a year,then have to be replaced.At least thats what I was told when I called about my temp probe giving an itemp error.I replaced the probe and that fixed the problem.I'd bet the PH probes are the same way.

 

[d2mini]

hmmmm.... i had to have my temp probe replaced too but the RKL was actually giving me an error.

I was noticing some salt creep getting near my electrical. Might be time for a wipe down.

 

[ccCapt]

It could also be the amount of co2 in the house. Do you have the windows opened more often or any changes to the inside air?

 

[Rcpilot]

Perhaps a leaky furnace or boiler flue pipe is dumping carbon monoxide into your house?

Do you have a co detector in the house?

 

[d2mini]

It could also be the amount of co2 in the house. Do you have the windows opened more often or any changes to the inside air?

I'm in Houston. You pretty much don't open windows here. :shock:
And even if you did, there's no cross ventilation. :grumble:
The ac turns on and off, but that's throughout the day. I'm seeing weird swings from day to day.

Do you have a co detector in the house?

Yup.

 

[Rcpilot]

Have you tried the old airline outside trick? Maybe run the airline from your skimmer to an outside o2 source and see if that helps?

Seams weird that you'd have such drastic swings on a day-to-day basis. When my pH was low, I was able to solve it with an airline stuck near a drafty window. That stabilized my pH a lot. But even before I did this - I wasn't having wild swings. I had LOW pH, but not the wild swings you describe.

I'm stumped. :shock:

 

[tankedchemist]

what kind of pH probe is it? There are certain types of pH probes that have fluid in them, which eventually evaporates or in other ways gets consumed, and needs to be refreshed. This can cause odd readings from day to day.

Also, regarding the calibration thing-- most pH probes are most accurate around neutral pH (7), but as the calibrations get "off" you find that higher or lower than 7 results in more drastic inaccuracy. in other words, as you deviate from neutral pH, the accuracy gets exponentially more "wrong"... it can't hurt to recalibrate. For the pH of our tanks, it's a good idea to use calibration solutions with pH 7.0 and 10.0. Should only take a few minutes to calibrate, and would eliminate one potential source of problem if you did it.

As a note, in labs, you calibrate pH probes on a daily basis, and do weekly maintenance on the probes (filling solutions, etc). I don't think it's necessary to be that anal about it for these purposes, but can't hurt to check.