Ph Probe Calibration Help

[Madreefer]

When calibrating probes do you use the 3 different solutions or just 1? It seems that if I use the 4 and than try to calibrate with the 7 or 10 I get inconsistant readings. I have a monitor that I use for the tank and a seperate controllor that I use for my reactor. When I swap the probes I get different readings. They are both Pinpont and using Milwakee solutions. What am I doing wrong?

[plutoniumJoe]

Tagging along.

[BlueTang<3]

i get the same thing the tank i am using 7 and 10 and my calcium reactor i am using 4 and 7 and they are both in the tank now as i am waiting for the reactor and there is a difference of .20 between the two with the 4 and 7 probe reading higher probes are both 2 months old and re calibrated a few times as i could not believe it

[Madreefer]

kind of frustrating as both my probes are fairly new. I've gone through 4 packs of the solution today already and have no more 7 left. Begining to think that it may be either a problem with the monitor or the controllor. Has anyone had issues with the Pinpoint products? My Pinpoint thermometer went for crap after 2 years.

[mark]

Only have one probe (got a while back from Aqua Digital) on a Milwakee monitor. I use 7 and 10 solutions and just go back and forth between them a few times, rinsing in rodi between solutions. Settles after about 3 cycles.

How's the battery on your monitor?

[Jason McK]

you should always use 7 and 10 for your Tank PH and 4 and 7 for your Reactor PH.

You will find differences if you switch the 2 that is normal. You need to calibrate to the closest numbers to what your measuring.

[MikeInToronto]

More precisely, you need to choose buffer solutions that bracket your target pH. Salt water is ~ pH 8.2 so you'd choose pH 7 and pH 10 as your buffers. Your calcium reactor has ~ pH 6.5 I think and that would be pH 4.01 and 7 buffers.