Im not big on looking up links but here is the name of THE ONLY HAND HELD units i will use anymore,its the Hanna Growcheck,its a rather large unit compared to most,shaped round like a hockey puck & about the same size,it has a 12 inch hard plastic dip stick attached that you can even stir up the rez with if you wish.
The led screen is real large & well lit so its easy to read ,its a single point calibration model that is the easiest i have ever used,most meters you need to enter the menue then follow a series of prompts to calibrate,some will say its no big deal but to me fumbeling round with shit suks so i hate doing it,anyways to calibrate the grow check you just turn it on & stick the probe in the solution of 7.0 or 4.0 ots your choice,if the reading dont read the 7.0 you used you just turn a knob up or down until the meter reads what its supposed to,the calibrate knob is pretty large too,bigger than a pencil erasor,maybe about the size of a womans finger tip.
Another ass kickin feature is the battery it uses,it runs on a tripple a battery,the unit is water tight & built for rough use,it can be left in the rez at all timez so all you have to do is turn it on & read.
HANNA GROWCHECK,look it up.
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