pH Meter Help?

Medi 1 said:

reason your thinking its off each time is a simple couple degree diff moves pH. so i bet it is right but the temp is diff each time....true readings are done at 77 degree for ph 7...unless like my meter it compensates for temps. i know those dont.
and hes still payin to much then. its under 10 bucks at any shop i used to buy at for the large bottle. i use the advanced shit right now as i find its the strongest...only need 2 to 3 drops per 25 gal rez to set mine here. and i pay 12 buck a liter for it...retail.

obviously skunk dont understand ph or nutrient uptakes, ph is the most important thing when growing for optimal nute uptake

Click to expand...

i think you need quite a significant temp change to effect ph. when i got the meter i did a test just for fun with tap water of 3 different temps. all the same ph up to the tenth. but my meter only reads to the tenth. although it was just water, i didnt try with any nutes. maybe it will be junk down the road, but so far it has not broke on me and works fine. also my friend has one of those expensive meters, http://htgsupply.com/Product-Hanna-pH-EC-Combo-WaterProof-Tester.asp we both tested some different solutions and both meters gave the same reading.

well mine shows for a 5 degree diff a .7 diff...and thats huge. means its 70 times more acidic at that different temp.
thats a pricey cheep meter in the link is all. this is what i use...reads every possible reading there is. and no batteries to rely on

http://www.getbluelab.com/shop/Bluelab+Guardian+Monitor.html

http://www.progressive-growth.com/proddetail.php?prod=blug1

the guys at my favorite head shop calibrated my meter cuz i couldn't get it either

Medi 1 said:

well mine shows for a 5 degree diff a .7 diff...and thats huge. means its 70 times more acidic at that different temp.
thats a pricey cheep meter in the link is all. this is what i use...reads every possible reading there is. and no batteries to rely on

http://www.getbluelab.com/shop/Bluelab+Guardian+Monitor.html

http://www.progressive-growth.com/proddetail.php?prod=blug1

Click to expand...

you're right. i just did a test and the colder the water was, the higher the ph. thank you for clearing that up. im not sure where i went wrong when i experimented before. guess my meter isnt as good as i thought.

i have a question if the OP doesnt mine me thread jacking. will the ph 7 calibrating solution be effected by temp change? i just did a test with that and the temp didnt effect it. so is ph 7, at a ph of 7 no matter the temp? not counting very drastic temp changes anyway. im only talking like a 10 degree difference or so. otherwise i was gonna say shouldnt the ph calibration solution be stored near the hydro system so the temps are very close to the same? also gave you a +rep for helping me get my facts straight.

your supposed to have them at close to room temp anyways. get the rez above 72 and pathogens can grow. 10 degree is huge diff in temp 70 would be fine to use and 80 isnt. thats 10 degree

everything we use should always be at room temps, water foods cal solutions pens and so on. how much it effects each of our readings will depend on meter quality

One thing I want to add is DO NOT USE DISTILLED WATER TO CALIBRATE YOUR METER, USE THE 2 SOLUTIONS. When I started out I thought water had a ph of 7 and I used that to calibrate, and unknowingly had my reservoir in the low to mid 4's for weeks. There is not as much harm in ph being too low as high from what I've read. Ph too high can kill the plant, ph too low usually just shuts out the plant from absorbing certain nutrients.