while searching for ph meters on ebay i found a hanna meter for about $40 shipped. it's new and comes with 7.01 solution. would this be a decent meter?
Get one with two-point calibration. You'll need 7.01 and 4.01. They're only as good as your care and patience. TDS meters are pretty quick to stabilize and pH meters take a bit longer. Follow the mfg's maintenance instructions and calibrate any time you suspect a bad read.
You get what you pay for and these things run into the hundreds of dollars and more. But before I'd waste money on an expensive pH meter, I'd get two cheap ones. As soon as the reads don't match, one or both have to be calibrated.
Tips have to be stored wet in most cases. You'll want to avoid distilled or ro water with pH meters, it'll spaz the read. 7.01 is fine as storage solution.
Cleaning solution is also recommended but I just rinse the tip with plain water and store in 7.01.
Just remember their reliability is only as good as your maintenance, calibration and storage. I probably average calibrating every 2 or 3 weeks. Probes usually last me 18 to 24 months before having to be replaced. Hanna's Checker is ~$25.
Write down the amounts of ingredients in your nute solutions. One good pH read and measured amounts thereafter is probably as or more accurate than [pH] metering every mix.
are there any chain stores that sell ph meters? i'd like to be able to buy one locally rather than ordering one. nearest hydro store is about 100 miles away so i wanna avoid the drive. i know they don't just sell them at wal mart but, what other stores would carry them?
I picked up an Oakton Ion 6 pH meter (retail $400) for $40 on the bay 4 years ago.
I had to buy a new double junction electrode for $80.
Just keep your eyes open for sellers who dont know what they have or which start with a low price. There's less demand for the lab grade stuff, so there's usually fewer bidders.
I like Oakton and have had zero problems in 4 years of owning my Ion 6 and Con 110 meters. Oakton makes some cheap shit for newbs, but they also make stuff which blows the run of the mill hydro stuff out of the water.
Go to an analytical lab and see what they have. Most likely a Thermo/Orion, Hach, Oakton or YSI.
I had an Extech condo meter, and while it was OK, calibration was a royal PITA and it never gave the same reading twice. Close, but no cigar. Sold it on the bay last year.
I also had a Hanna Grocheck combo pH and condo meter which was good, but the condo electrode was non replacable. Sold it on the bay last year.
Meters with replaceable electrodes will be your best bet over the long run. The electrode is usually the part which fails.
Like Disco said, proper storage of the pH electrode is critical. The glass bulb should be kept wet with either pH 7 buffer solution or eletrode storage solution (I believe the ESS is potassium hydroxide). You can rinse your electrode with tap or distilled, but storing your electrode in water will cause it to fail.
If you can get a meter with 2 point calibration all the better. I'd suggest the 4.01 and 7.0 pH buffers. Since most of our work is in the 5.6 to 6.5 pH range, that's where you want to be most accurate. I have the 12.01 buffer, but only cal using it once or twice a year.
Went through 5 hannah trimeters in 3 months, 2 more have failed wihin the year. Nutradip trimeters are junk. Having good luck with a bluelab one at the moment, but i will never buy Hannah shit again.
Hanna makes some good, lab grade stuff, but most marketed towards growers is junk.
Quality is your best value.
Can you replace the electrode on the Bluelab or is it some proprietary bullshit which only works on their meters.
Most meters with replaceable electrodes use a standard BNC or DIN connectors.
I replaced a cheap Hanna probe a few months ago. It still has to be calibrated every few weeks. Reads still take ~60 seconds to stabilize. Other than that it works fine.
IMO don't get Hanna, they are not fully waterproof. I use a bluelabs combo metre it reads PH, EC, and temps and I'm happy so far, it's also 2 point calibration. Here's a youtube video with more information... http://www.youtube.com/watch?v=JY1DfrToqIY