pH right on point
- Thread starter SilverBulletPRN
- Start date
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Thanks, @Sral that'd be much appreciated. I am somewhat worried that my pH reading gets a tad high, I read that 8.5 is the recommended maximum. I'll be traveling in the end of next week, with no control over my tank during the period of about 3 weeks, and I am afraid that pH might grow even higher. No skimmer cleaning will be performed in this period - that may probably count towards decreasing the pH value, but feeding will be reduced to one cube a day instead of current 2 cubes - so, not really sure how this all will affect the parameters in the tank...
@SilverBulletPRN sorry for hijacking your thread with my concerns, but I thought this is a related discussion and is not worth opening a separate thread. If you object, I'll move elsewhere.
gbroadbridge
2500 Club Member
Have you recalibrated with fresh buffers?
8.5 consistently indicates a measurement error
8.5 consistently indicates a measurement error
Sral
Valuable Member
That's a problem with the scale I guess, since the lowest value is 3.8 and the highest something like 10, you can't see the small changes that might be in there. Additionally, the timeframe is only 3 hours or so, so you wouldn't expect wild pH changes anyway as long as your dosers aren't stuck and dump a month's load of chemicals in there ^^
Sral
Valuable Member
Alright, here are some links:
- RoboTank pH circuit Accuracy Thread
Goes over some background info and testing on the RoboTank pH circuit, but also tries to address somebody's problem with fluctuating pH readings.
- Conversation in the reefPi Main Thread with PlantedAquaChicago
- Just started a common pH measurement problem Thread
I will include the conversation with PlantedAquaChicago there as well soon.
- RoboTank pH circuit Accuracy Thread
Goes over some background info and testing on the RoboTank pH circuit, but also tries to address somebody's problem with fluctuating pH readings.
- Conversation in the reefPi Main Thread with PlantedAquaChicago
- Just started a common pH measurement problem Thread
I will include the conversation with PlantedAquaChicago there as well soon.
Yes, I have a fresh Pinpoint probe, it has been in use for about a month. Without calibration it was reading a max of pH8.35 in the tank. Then I calibrated it with fresh solutions made with the pictured pH6.86 an pH9.18 buffers, dissolved in 250ml of RO water, and now it maxes at pH8.45
I also have a pH4.01 buffer but since Reef Pi does not support 3-point calibration, and since my measurement is in the upper range, I am not using that packet.
P.S. I am using the Robotank circuit
Not sure if this is about my circuit, or that of SilverBulletPRN
My measurements show a repeated swing between 8.15 and 8.45 on a daily bases.
The graph by SilverBulletPRN shows a value around 8.18, but the scale is expanded from 3.6 to 9 - probably because the probe was taken out of water at some point.
Sral
Valuable Member
Sry, I was absolutely confused about whom was talking to whom XD
Sadly I cannot help much with recommended pH values in reefs.
If your meter is calibrated, shows a nice daily swing and reads correct values in the calibration solutions it doesn't sound much like a measurement error to me.
SilverBulletPRN
Active Member
Yes, I used atlas scientific for calibration.
I was calibrating with Atlas Scientific's pH 7, removed it and washed with regular RO water (which probably caused that drop, then pH 10 for my second point. It has been steady at 8.1-8.3 pH. Unless I missed something here?
This was all on on the Raspberry Pi 3B+ with Leviathan's Board, Atlas Scientific EZO pH circuit with their isolated EZO carrier board.
Sral
Valuable Member
Looking great, I simply didn’t expect that calibration to show up in the graph. Looked like an error to me
Interesting though, that washing with Reverse Osmosis (RO) water causes a reading of 3-4 pH. Did not expect that.
gbroadbridge
2500 Club Member
RO water has no pH.Looking great, I simply didn’t expect that calibration to show up in the graph. Looked like an error to me
It can read anything
You probably mean to say that RO water has zero KH, and therefore its pH may swing easily.
Usually it grabs carbon dioxide from the air and becomes slightly acidic. Probably down to pH5.5.
But I think there is no way it will go down to pH3-4, that is too acidic: pH value is based on logarithmic scale depending on the H+ ions concentration
gbroadbridge
2500 Club Member
