On the subject of pH testers

[Victorytoker]

I've recently spoken with somebody why spent near a grand in hydro setup and yet had limited success. After a lot of diagnosis we discovered his ph tester was way off, by about 3.0 meaning if he were aiming for 5.8 it would in fact be 8.8, this got me thinking that my wife who grows cacti also has a few p.h testers, so I did a comparison of her vivosun $20 tester vs my same identical tester, vs my new apera tester that I have been waiting for in mail for a bit ( have been new again to hydro for about a month ) here are the photos showing the actual verified p.h. ( the expensive meter ) vs the other 2.. you will note 1 of the cheap ones is not too far off, the other worse. The expensive meter as well as the vivosuns have just been calibrated before checking this bucket. Spend a bit extra on a quality meter, it is critical.. buddy online lost 6 of 8 plants learning the hard way and was using the exact same 2 meter as the two in photo.

Spend a bit on it, and have a $6 chemical tester and proper calibration solution. Calibrate at least monthly, weekly preferred.

 

[xave420]

The ph meter on the left would bother me but if my ph was either 6.25 or 6.34 I’d be okay with that either way as long as the next feeding I’d try for 6.4

 

[Victorytoker]

The ph meter on the left would bother me but if my ph was either 6.25 or 6.34 I’d be okay with that either way as long as the next feeding I’d try for 6.4

The point was that the actual ph of the water is 6.35, this was before adjusting to 5.8 ( dwc hydro )

 

[TorturedSoul]

Those cheap disposable (probe is not replaceable) pH meters probably have a stated accuracy specification of ±.2 pH. Which sucks, but in theory, two in the same sample could differ by .4 in their readings and still be "up to spec," lol.

Mine displays two decimal places (e.g., 5.85) but I didn't buy it for that; I bought it because it has a stated accuracy of ±.05.

 

[Victorytoker]

Those cheap disposable (probe is not replaceable) pH meters probably have a stated accuracy specification of ±.2 pH. Which sucks, but in theory, two in the same sample could differ by .4 in their readings and still be "up to spec," lol.

Mine displays two decimal places (e.g., 5.85) but I didn't buy it for that; I bought it because it has a stated accuracy of ±.05.

Mine was for the accuracy and the water proof. I hate the idea a being sol cause a meter, for water... got wet

 

[Mcdoolit]

I have just been using the cheap test kit and haven't had any issues. I'm buying another tds, so I went ahead and ordered a cheap digital ph tester as well, but I'll most likely use em along side each other.

 

[Mcdoolit]

Scratch that...the digital ph meter is still in my cart, yea says accuracy of +/-2. No point in buying that shit lol. If my test kit has worked good for me this long, might as well just keep using it.

 

[TorturedSoul]

It's probably .2

 

[Mcdoolit]

This is it.

 

[xave420]

I’ve used the cheap yellow ones for $7 and never had a problem just as long as you have a bottle of 7.0 calibration solution. I find I gotta re calibrate every week or 2 which sucks but is what it is. It only goes out .1 to .3 for example. Maybe one of these days I’ll splurge and get a blue labs one lol

 

[Edzzed]

I haven't needed to check my pH tester recently because this grow is only 10 days old. That said, I did check my tester in vinegar. It has a pH of 2.4 That's how I set the calibration.

 

[ThunderThx]

This is it.

The ph meter is .05% accurate the other blue tester( which test contration levels) is the one that +/- 2

 

[SoGnotSOG321]

That is a much to critical part to go cheap on when you go with these wet grows. I have soil so I dont worry to much about having the yellow stick bluelight special. I checked and calibrated it in all three (distilled water) solutions when I bought it. I have checked the solutions several times and the numbers are exactly where they were when I calibrated it, not even a .01 difference.
I did see a risk in only having one, so when I saw the combo pack with the tds/ec ppm temp meter together for 18 I picked it up.
Would I use these and expect a dwc to run flawlessly? No. There's to many checks to do versus a soil grow. I wouldn't expect it to last as long using it every day multiple times a day in different solutions etc. I know practically nothing about dwc except the oh Shirt! WTF is wrong stories I've read here but also the awesome farmers who make it work so beautifully amirite?

 

[Bob Loblaw]

All of my grows have been hydro (6 or 10 grows), I have bought 2 testers & returned 1...waist of $ IMO I don't use them at all.

My test juice works just fine at about $9/year. Get the refill it's way cheaper and use a smaller test bottle.

From what Ive read a little bit high today and a bit low tomorrow is just fine in fact it's preferred... seems to be working for me so far. A $100 tester would be nice but is certainly not necessary.

 

[Mcdoolit]

I've used my cheap tds and the cheap ph test kit my entire grow with no issues. I did end up with nutrient burn, but it was my fault. I thought they could handle a higher ppm...and well they couldn't LMAO. Luckily, I saw it quickly and have been topping them up w ph'd water only. My cheap tds only lasted 3 months. It still works, but can be flaky sometimes.

 

[TorturedSoul]

My cheap tds only lasted 3 months. It still works, but can be flaky sometimes.

Ironically, EC meters ought to last virtually indefinitely. All they do is measure resistance and perform a simple calculation or two. We can do the same thing with a DVOM set on resistance (Ohms) and a calculator or piece of paper and pencil/pen, although it's a bit of a PITA compared to turning a handheld tester on, sticking the end in a sample, then reading its display.