i was looking on ebay for an affordable ph meter because the fish tank kit isnt really cutting it anymore.
http://cgi.ebay.com/PH-PPM-TEMP-TDS-EC-CF-METER-WATER-HYDROPONIC-TESTER-H55_W0QQitemZ220421933909QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item33522bcb55
does anyone know if this is a good meter. It looks like itll do everything i want it to. was wondering if anyone has this unit and if its difficult to calibrate. I dont know much about digital meters, are they difficult to calibrate. This one doesnt come with a solution wondering if it'll be easy to use and accurate.
It's really not... You would be much better off going with something from Hanna... The pens are quite inexpensive... But even they are not that good... I'm sure quite a few people will be happy to argue this with me... But it's the truth... However anything is probably going to be more helpful to you then an aquarium test kit... It takes a lot of practice and precision to use one of those well... Though they can be very accurate!
Couple more points... A continuous monitoring meter is really not the best way to go... They have some issues in that the probes get fouled and can drift. And the way most people use them with the probes fixed to the sides of the res is also just kind of wrong... To set up a continous monitoring meter properly you need the probes in flowing water... Like for example the pressure relief off your pump.
And even then... It's more useful as a sort of first line evaluation... I would never use one to mix up solution for example.
I have a friend who worked in a very prestigious toxicology lab for a long time, and I've watched and helped with a fair amount of testing.
Truly accurate, high quality equipment cost thousands of dollars. Company's like fisher scientific, Orion, etc are your go to people... Hell, their calibration solution costs more then that meter
Nice thing is, if you look around on ebay you can get used equipment from these companys for pennys on the dollar...
I picked up a Thermo Orion Ec/TDS meter for $75 recently, and a probe for about 45...
Don't be discouraged though... If get yourself a $75 hanna pen, treat it well, clean it regularly... Calibrate it... You'll be fine. Calibration is pretty simple... On most meters it's 2 point... Meaning first you will dip the pen into a known low Ph solution and make some kind of adjustment until the display reads the same as your standard... A lot of times this will be a screw... Some of the more expensive hanna meters will do it automatically. Then you will do the same with a known higher ph standard.
If you go with something like the Hanna, buy it new... Used gear like this is often abused and it's so inexpensive it's not worth the hassle.
T.M.H.
