Electronic PH testing

[pink66]

Hi all, just wandering around Ebay and have come across Electronic PH testers. Has anyone had experience with these and I suppose the big question is, do they work???

thanks very much
Sharon

[DIY]

Yep they work :thumb

Try and get one that has 2 point calibration and if possible one that comes with calibration solutions to save buying seperately.

With pH probes - both constant monitoring and pen style press and hold - accuracy comes down to being calibrated. Over time the readings "drift" so you need to re-calibrate regularly. For constant monitoring - how regular depends on quality of the probe the water being tested but every 6 months is fairly typical. For press and hold pen style, I would calibrate if it has not been used for a month or so, for the best accuracy you can calibrate before each test :shock: ... but most don't go to that extreme

2 point calibration means you calibrate it at pH7.0 and then at either pH4.0 or pH10.0. Single point just calibrates at pH7.0

[pink66]

Hi Lindsay. I should have know just to ask you in the first place :wink: :wink: . There are two distinct types on ebay.. on a pen type and the other has 2 solutions.. I do not know if they are good quality or not.. I also do not really like buying from OS on ebay as I feel I would have less comeback if something was not right..

But I am looking at my options as when I test my PH because it is at the high end of the "mid" range version and at the bottom of the "high" range version.. I seem to have probs identifying.. :cry:

[DIY]

The pen types are all pretty similar from what I have seen, in general they work well and are priced reasonably. You can get them from places like jaycar, hydroponic stores, larger LFS etc. The downside to the pen type is once the probe wears out, the whole pen is a throw away. I think the lifespan is quite reasonable though.

The other type is continuous monitoring, where the probe is always in the water. These wear out the probes much faster obviously but nearly always the probe is replacable (some of the cheapies on ebay aren't). Often the continuous type is used with CO2 where the "tester" is not just a "tester" but actually a CO2 controller.

Interestingly the actual chemistry of a probe is sort of like a battery (very loosely) so a decent quality replacement probe is often more expensive than a pen type tester, but that is partly due to the fact it needs to have a reasonable lifespan while being used 24x7.

Unless you are considering CO2 - you are probably best of getting a basic Pen type tester from somewhere like Jaycar.

I can't read pH with any accuracy from colour charts personally so electronic testers are by far my preference :wink:

[Merrilyn]

Yep I agree. The pen type ones are much more accurate than the test kits.

Have a look through the range available at one of our online sponsors. Try to get one with the auto off feature. I used to forget to turn mine off, and went through batteries at a rather fast rate.

My new one, purchased from ASA has an auto off switch. Love it.

[DIY]

:banghead Should've thought about the sponsors - even better :thumb

:stupid

[pink66]

Thanks DIY and Merrilyn, now I know they work.. Online to check out the sponsors I go.. I must say, until I tripped over them on ebay (whilst looking for something else entirely !!) I would not even have known they exist..But I can see they are going to save me much time and effort...

Well, that is something new I have learnt today..

:wave2 :wave2 :wave2