I've been using the drop-based pH tests from Aquarium Pharmaceuticals, and I always have trouble reading them. I thought I was doing ok, but a recent situation with my fish caused me to start checking pH more frequently and more carefully. While doing this, I became convinced that I am not accurately interpreting the results because of my trouble telling which color the water matches up to.

So I am thinking of buying a cheap digital pH meter. I was wondering if anyone else has one, and if you do, would you recommend it? Also, how much can I expect to spend for one?

Thanks.

It is an interesting idea. I see a lot of digital PH tester in ebay with a decent price. And seems if you have one, you can use it for a long time. But I don't know how good they are though.

We use WTW pH meters in our wastewater treatment lab-scale reactors. These units are very accurate, hardy, and easy to use. They are not cheap. They cost ~$500. Oakton has low cost meters $80-$100. These are not as good or convenient as the WTW but should work very well for an aquarium setup.

I've been looking around now and saw some on ebay for about US $30.00. I'm trying to decide if any meters that cheap could really be any good. They claim to be accurate to +/- 0.1 pH, but who knows?

Do we need to do any maintainence for those kinda device? For example, refill or replace something.

pH meters will need to be calibrated - requiring calibration solutions, etc. I find that using one in a home situation more bother than it is worth. It is one thing to use them at work - another to have all the equipment at home. (I am a bit anal about those solutions at work!)

I, too, have been more than frustrated with the various pH test kits available for tanks. My pH is always somewhere between the "high" and "low" test - requiring me to test with both a high and a low test kit and average the two to get any sort of idea of where the pH is! I HATE that.

I have a swimming pool. We have a plastic box that came with the test kits for that . It had a reservoir on one side that has colored pieces of plastic up the side to match color of the pH test. This test requires only phenol red drops and the water. It goes from 6.8 to 8.6. That is a wide enough range that my 7.0-7.8 pH is in the middle. The colors are quite distinct and easy to read. The phenol red is only $1.66 a bottle and a bottle has lasted me over 1 year on all my tanks. I am pleased with this alternative solution.

I would love to have a pH meter in my home, but am not prepared to spend the money or the trouble it takes to keep it properly calibrated.

Yah, I am afraid with the pre-calibrate one also. Don't know how good(stable) it is. Well..

Do you think that most pool supply stores would have a PH kit like that? Sounds like a miracle test kit to me.

Daryl that pool tester you referred to sounds great. Is it any pool tester? That might be worth looking into.
You are just so ingenious!!

That's a good tip on the pool pH kit, Daryl, but I still think I'd rather have a pH meter and eliminate the need to interpet color altogether.

I'm aware of the more costly/bulky plug-in models used in labs (used quite a few myself over the years) and I wouldn't want one of them for home use, either.

I'm also aware of the need for calibrations, but I don't think that'd be a really big deal for weekly testing. Seems to me you can usually do a 2-point calibration in under a minute, then test for pH all while you're waiting for your other tests (nitrate, etc.) to develop.

I guess I should've been more specific in my original question and asked this-

Does anyone have any experience with the hobby-type, battery operated "stick" pH meters? If so, have you found them to be reliable?

I think I've answered the cost question myself by looking at some online stores and on ebay- they seem to cost anywhere from 30-100 dollars depending on brand and where you buy them.

I use the Hanna pHep. It measures both pH to two decimal places as well as temperature to one decimal place. It automatically adjusts for the temperature of the water (which can affect the pH readings on other types), so you can calibrate it in solutions a different temperature to your tank water. You have to calibrate it every two months or so by sticking it in two different pH solutions at either end of the scale. These pH testers are widely available.



Or you can get a simpler model/brand which only does the pH (no temp.). Or even one which only does pH to one decimal place, which will serve your purpose just as well (ie, you get a pH reading of 7.2 instead of 7.16, which is no big difference).

Thanks for the info awrieger. Have you found it to be reliable? Also, how often do the batteries need replacing?

i'm also interested in purchasing a digial ph meter. recalibrating it every 2 month isnt bad, but the tips replacements are very expensive!

has anyone purchased these pocket sized ph meters?
http://cgi.ebay.com/Hanna-pH-TESTER-METER-...1QQcmdZViewItem