Ph cal

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rimai
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Re: Ph cal

Post by rimai »

You should increase slightly.
Roberto.
jemw
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Re: Ph cal

Post by jemw »

rimai wrote:You should increase slightly.

Do I have to reboot controller?
_____
Jim
rimai
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Re: Ph cal

Post by rimai »

Yes, for every change you make on the PHMax value.
Roberto.
jemw
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Re: Ph cal

Post by jemw »

Not sure what is going on, but the pH calibration function appears not to function correctly. I finally had to take the initial readings given by the function and then read the pH7 and pH10 calibration fluids and manually adjust from within ReefAngel Client. It took me about three adjustments with each the pH7 and pH10 calibration fluids to tune it in. My pH probe is now in sync with my pH test kit.

Needless to say that cycling the equipment that many times adds to the possibility of failure. :( You really need to address this issue.
_____
Jim
rimai
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Re: Ph cal

Post by rimai »

Thanks for the observations and it's been logged for future updates.
Roberto.
rimai
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Re: Ph cal

Post by rimai »

Did you rinse the probe before transfering and let it stabilize on the pH 10 for while?
Roberto.
rimai
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Re: Ph cal

Post by rimai »

They shouldn't be the same.
What happens to those numbers if you dip the probe into vinegar?
Roberto.
alexwbush
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Location: San Diego, CA

Re: Ph cal

Post by alexwbush »

mine was weird in that my numbers were:
211 (7.0)
523 (10.0)

Right now reads 7.82
Sebyte

Re: Ph cal

Post by Sebyte »

For a Standard test that is cheep and repeatable I use the 20 Mule Team Borax test.

Borax or sodium metaborate solution will always be at a pH of 9.18 + 0.02, even if you do a poor job of making this solution.

Use a pint of water (473ml) and add a half teaspoon (1/2 level tsp.) of borax to make a resultant pH standard solution with about 2 gm of sodium metaborate per 473 ml or 4.3 grams of sodium metborate/litre.

Although using this method to make the standard will only result in an accuracy of about plus or minus 10% of the lab standard sodium metaborate pH calibration solution, for me it's a good and cheap test to make sure the probe is on the mark. Compared to commercial solutions you can afford to use this test every week when you clean your probe.
rimai
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Re: Ph cal

Post by rimai »

Add these 2 lines to your PDE file, just bellow the ReefAngel.Init()

Code: Select all

ReefAngel.PHMin=520
ReefAngel.PHMax=801
Roberto.
rimai
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Re: Ph cal

Post by rimai »

sorry. forgot to add ;
use this one instead:

Code: Select all

ReefAngel.PHMin=520;
ReefAngel.PHMax=801;
Roberto.
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J_C
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Re: Ph cal

Post by J_C »

Is there a way to change the values I calibrate to? I only have available pH 4 and pH 9 calibration solutions from all of the LFS in the area. I could order the pH 7 and pH 10 calibration solutions, but then I'd have to order the big bottle.
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rimai
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Re: Ph cal

Post by rimai »

It's simple interpolation math.
You can get the numbers from pH4 and pH9 and calculate both 7 and 10 values.
Roberto.
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J_C
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Re: Ph cal

Post by J_C »

awesome, how would I accomplish this?

Just a thought from a noob and some reading

pH 4 reading would be something like 398

pH 9 reading would be something like 903

I would just change the numbers to make them work for the pH 7 and pH 10, something like this?

adjust pH 4 reading to 698

adjust pH 9 reading to 1003
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rimai
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Re: Ph cal

Post by rimai »

Correct. You just need to calculate the simple interpolation math.
Not too hard, but if you get problems, let us know.
Roberto.
beaker77
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Location: Columbia, IL

Re: Ph cal

Post by beaker77 »

When I finish the pH calibration and leave the probe in the 10.0 solution the controller shows the pH @ 9.87 (which is close enough). But when when I remove the probe from the 10.0 solution and put it in my sump the reading on the controller jumped to 20.21. I put the probe back in the 10.0 solution and the display now reads 19.43. There is no way the pH in my tank is that high. I tested with a Salifert pH test and it shows 8.3

Rebooting the controller doesn't make any difference. I've repeated the calibration 4 times now with the same results.

I've only had the controller setup for just over a week now and my probe is new and never been exposed to air.

What can I do?

Thanks
rimai
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Re: Ph cal

Post by rimai »

Did you do pH7 first?
Roberto.
beaker77
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Location: Columbia, IL

Re: Ph cal

Post by beaker77 »

rimai wrote:Did you do pH7 first?
Yes
rimai
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Re: Ph cal

Post by rimai »

Which numbers did you get on screen while doing the calibration?
Roberto.
beaker77
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Location: Columbia, IL

Re: Ph cal

Post by beaker77 »

7.00 = 243
10.00 = 360
rimai
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Re: Ph cal

Post by rimai »

Does not look right.
Is the glass bulb in the tip of the pH probe intact?
Roberto.
beaker77
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Location: Columbia, IL

Re: Ph cal

Post by beaker77 »

OMG, There isn't a glass bulb on my probe.
rimai
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Re: Ph cal

Post by rimai »

You got PM
Roberto.
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J_C
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Re: Ph cal

Post by J_C »

Calibrated to pH 4(244, adjusted to 544 via phone app) and pH 10(840, don't know what to adjust to since I can only go to 1024). Been playing with the numbers and I can't really find my sweet spot. It's read from 6.6 to 8.9. The only other way to check pH is a redsea kit, showing 7.8. What am I doing wrong? Adjusting all from the phone app.

I let the probe sit in the solutions roughly 10 min (I was worried about the temp variations so I cut it down a little), rinsed between solutions also.
Last edited by J_C on Tue Apr 10, 2012 9:22 am, edited 1 time in total.
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rimai
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Re: Ph cal

Post by rimai »

544 for pH7 and 840 for pH10 seem correct numbers.
Roberto.
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J_C
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Re: Ph cal

Post by J_C »

The issue is that those settings make my pH read ~6.6
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rimai
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Re: Ph cal

Post by rimai »

What were the numbers you got for pH4 and pH9?
Roberto.
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J_C
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Re: Ph cal

Post by J_C »

I calibrated to 4 and 10. I got 244 and 840, respectively.
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rimai
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Re: Ph cal

Post by rimai »

Oh, one other thing. Doing through the phone, Client or any app will require you to reboot the controller after you save the numbers.
Roberto.
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J_C
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Re: Ph cal

Post by J_C »

Thanks, rebooting now

Reading 7.6
RedSea is currently reading 7.8

Changed the pH10 to 740, the RA is reading 7.87 now...fixed
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