thaerin

All right, I admit it. For the life of me (or rather, my fishes) I cannot accurately read those bloody test kits. The eye doctor says I'm not color blind but I wonder sometimes. Every time I test my water then have the LFS test it for me, I'm not even close to what they have. I thought my pH was off the scale (8.1), they said it was 7.2. I have no idea if it's staying constant and I don't like it.

So for the sake of my sanity, I'm going to get digital test kits for what I can. First off will be the pH tester, although if anyone can recommend a digital test kit to measure most of the needed tings for an aquarium, that'd be grand.
http://cgi.ebay.com/ws/eBayISAPI.dll...500573870&rd=1
http://cgi.ebay.com/ws/eBayISAPI.dll...365394964&rd=1
http://cgi.ebay.com/ws/eBayISAPI.dll...879891738&rd=1

Couple of options I've found. Preferences?

pineapple

Good luck. I would advise you try another source rather than the one you linked above. That person has too much negative feedback. The Milwaukee pH meters are reliable. Hannah are not too bad either, but they don't seem to last as long IME.

Try one of our sponsors.

Or Aquatic Eco-Systems for example.

Andrew Cribb

glenhead

I have the Hanna Checker 1 from proaquatica. Good vendor, instant shipping. The pen has worked well, though it does take it 20-30 seconds to settle on a big pH difference (3+ points).

If you do get a pH meter, you MUST get a pair of calibration solutions (called standard buffers) for it. pH7 checks one side, and choose the direction that your tanks go most - pH4 for more acidic tanks, pH10 for more alkaline. The Checker from proquatica comes with three little capsules of standard buffer powder (4, 7 and 10) to make 20ml (be sure to use distilled water to create them - I didn't on the first go-around) for initial calibration. I trusted that the calibration would last a long time, and was horrified when I took a sample to the LFS and found out that the water that my pH meter said was 6.5 was actually 5.3! Both of the calibration screws were off by over 1/2 point. Lesson learned!

I got a set of standard buffers from a laboratory supply firm (I'll post another item in this thread with the address) and paid $23 total (with shipping) for 500ml of 7 and 4. I bought a couple of 29 cent 10ml plastic test tubes at a local science-fair shop, and fill them about 1/4 full to calibrate. I calibrate my pen at least once a week, and use it daily. It has settled down to where it never drifts by more than a few hundredths in a week.

HTH

Laith

By the way, the one parameter that cannot be tested by your lfs is the pH unless they come to where your tank is set up. By the time you get the water sample to them the pH will have changed...

But I agree with you re electronic testers. When I get rich, I'm going to get one of those electronic colorimeters to measure everything!

gnatster

I've had a Hanna unit for 7+ years. Takes about 30 sec to get an accurate reading. I calibrate it about every 2 weeks and it reads within 0.1 of my Milwaukee controller. Mine was purchased at a local hydroponics shop for about $29.

thaerin

Even if it's in a sealed Ziploc bag and tested at the store less than 2 miles from my house?

JanS

I picked up the Milwaukee Smart pH portable meter for $25 in a mass buy, and it's been very quick and accurate.

thaerin

how do you store a Hanna pH meter when not in use? Any need for special liquids or something?

glenhead

The directions with the Checker say to store it with the probe wet, preferably in probe-storage solution. The tip of it stays pretty wet if you don't shake it, and the little cap that comes with it holds the water well - I just put the cap back on with the probe wet. I've seen several discussions where people have said it really doesn't matter with the inexpensive probes - the really expensive exotic metal ones are the ones that need fancy protection. Since I got the standard buffer solutions and have been calibrating mine regularly, it's never off by more than .03 in two weeks. I keep it on top of my tank.

One other weird thing. The tester loses its mind when my All-Glass 110W compact fluorescent fixture is on. With the lights on, it says the pH is below 5! Switch the lights off, and it reads correctly immediately. The normal fluorescent fixtures on the other tanks don't have any effect, but the CF fixture freaks it out. Something to watch for...

thaerin

Does the temp change with the compact on? I noticed soem more expensive checkers mentioned something about correcting for temperature when teting pH.

Anyway, so the Hanna works well but you just need to make sure to calibrate it every few weeks?