ph meter recommendations

[crawlintbss]

as title says... recommend me a good ph meter. i have a basic eletrikcity ATC meter this pos wont stay in calibration. i can test it and get it calibrated to 7 then ill test some 1 gals and use the drops as backup precautions and the drops will show way different. ill go test the meter again and then its reading .3 higher.

id like something 50$ or less that will stay in calibration. i understand i nee it to cal it every once n while but this one is just rediculous. its caused me a giant headache of low soil ph because it was so far off,causing cal and mah lockout during my flowering.

any links or names would be awesome. if it has to stay in solution that is fine aswell.

thanks

 

[az2000]

I've used the same etekcity meter for a year, no problems. It's not clear from your post whether it's going out of calibration by testing calibration solution, or comparing to liquid drops.

I use KCl probe storage liquid (6 drops in the cap). Occasionally I soak in probe cleaning solution. It holds calibration for a long time.

If I were going to get a higher quality ph pen, I'd buy a BlueLab ph pen. That's about $100.

 

[crawlintbss]

Its just not staying in calibration at all.

I use the drops that come with ph up/down as a 2nd check against my meter. as long as my color is in the vicinity of what the pen says i trust the pen. but recently my pen will say like 6.4 but the drops are giving me 5-6 coloring. Ill test the meter in the solution and it will read too low by .3. Ill calibrate it back up, then do another gallon of water, and it will be off again by like .4 higher. So i was obviosuly close but its not giving me accurate readings.

I did notice the ph calibration solutions say @25c. Do we need to get that solution to that temp to be accurate? I thought since this meter is ATC ( temp control ) that it shouldnt matter since the pen calibrates for the temp.

Maybe im doing it wrong. ive also usually calibrated with both solutions. Calibrate to 7, then calibrate to 4.01 ( same instructions for when first setting it up ) Should i possibly store in solution? This one doesnt recommend that you have to. Just says to dry off when done.

Thanks AZ! You are always a great help!

 

[Grojak]

everyone says Blue Lab and I don't question their balling but their $200 bucks…. I've been using a Millwaukee MW101 ph meter for 2 years rarely needs calibration, I'll check it and it may be .01-.03 off and only the 4.01 seems to go out of calibration and the probe is still the original (I should replace it any day). It also has something you usually find in higher end models, it has a dial to set it for the exact temp of the water you're testing. It does not have a built in thermometer though, their higher end version does I think. I paid around $65 on Amazon and worth every penny, oh and its processor is pretty good too doesn't take 5 minutes to get a reading. I had the red Hanna meter before it blew chunks.

 

[yelmkram]

Blue Lab Combo Meter, $200 is nothing if you're doing right.

 

[crawlintbss]

I got no problem spending a few bucks but $200 is a little too much for me right now, and for what i want to spend on a meter pen. id prefer the 50$ range. Now if i was on a larger scale for profit id justify the $$ but for personal I cant fathom $200 for a pen right now.

 

[az2000]

I did notice the ph calibration solutions say @25c. Do we need to get that solution to that temp to be accurate?

You can adjust your reading to the temperature using a chart like this. (<<link). But, the difference between 50F and 80F is about 0.05 ph.

I thought since this meter is ATC ( temp control ) that it shouldnt matter since the pen calibrates for the temp.

Maybe im doing it wrong. ive also usually calibrated with both solutions. Calibrate to 7, then calibrate to 4.01 ( same instructions for when first setting it up ) Should i possibly store in solution? This one doesnt recommend that you have to. Just says to dry off when done.

I calibrate to 7.0. I have some 4.01 and used to check the accuracy at that range, but I always calibrate to 7.0.

You shouldn't let your probe become dry. You should rinse it in tap water, and put a few drops of water in the cap. Storage solution (KCl) is better. But, a few drops of water is better than letting it dry. The problem with using water is it will eventually get a film or gunk. That's when the cleaning solution comes in handy.

I have a Milwaukee PH006 too. I don't like it. It's been flakier, the calibration screw is too delicate. I measure with both pens. They'll both calibrate to 7, but they can give different readings in different nutrient solutions. Or, they'll settle to a number faster than the other. Seems to have something to do with the ppm strength. They might read 0.2 to 0.3 different at times. I split the difference or lean towards the Etekcity, knowing it's been more stable.

In soil you don't need to worry about ph too much. Use dolomite in the soil, vary your ph between 6.3 and 6.7. If you were in hydro, ph would be more of a concern because you don't have the soil's ph-affecting ingredients acting as a buffer.

Contradicting what I said about letting the probe dry out, I have had a couple of instances of erratic behavior. Usually because water got inside. I remove the battery compartment and probe cap and let everything dry for 8-12 hours, including the probe. It goes back to stable behavior. You might try letting your probe dry for 6-8 hours, rinse and calibrate. See if that helps. Get storage solution. You'll definitely want it if you invest in a better ph pen.

 

[crawlintbss]

Thanks AZ. Ill try storing with some water next time.

it did start to get irradic near the end of my mixing yesterday. Like jumping from 7.00 to 6.43 to 6.99 then down to 6.5, while mixing nutes. Its been sitting out to dry for 24hrs so i will see tomorrow. Never been dipped past the line. always just fill small amount in solo cup and let pen sit in there to stabilize.

I will try recal again with it tomorrow. Does the temp really make much of a difference since these at ATC?

ps - i always use distilled water. we have well water here and the ppms are to crazy. one day its 130 next its like 600.

 

[waterdawg]

I've had an oakton, 2 blue labs, and now use a cheap HM which is hands down the best for me. It is two years old and nary a problem. Store it in tap water and calibrate rvery week for piece of mind.

 

[jb5355]

i use a regular blu lab ph meter. its a little more than you want to spend but its dependable
its about $85

 

[az2000]

Never been dipped past the line. always just fill small amount in solo cup and let pen sit in there to stabilize..

When either of my pens became erratic it was after rinsing off and some water splashed onto the LCD screen. I put some clear packaging tape over the screen which stopped that from happening.

I would pull the battery compartment from the top, and leave the probe's cap off, let it sit for 8 hours. Then recalibrate.

 

[crawlintbss]

Will Do AZ!

Do you tihnk i need to get fluid to @25c like bottle says or okay since its ATC? just dont get why when i started yesterday before mixing all my gallons that i calibrated to 7.0. Then after i did 2 gallons and the color coming out dark yellow for 5-6ph, i check the pen in the solution and it was reading 6.73. I follow the directions and let it sit for at least a minute then calibrate. always cleaned with distilled too, even between tests in the solo cup.

 

[az2000]

Do you tihnk i need to get fluid to @25c like bottle says or okay since its ATC?

I replied to that in a prior post. The correction for 50F versus 80F is about ph 0.05. It's nothing to worry about, especially with soil.

just dont get why when i started yesterday before mixing all my gallons that i calibrated to 7.0. Then after i did 2 gallons and the color coming out dark yellow for 5-6ph, i check the pen in the solution and it was reading 6.73. I follow the directions and let it sit for at least a minute then calibrate. always cleaned with distilled too, even between tests in the solo cup.

You might stop using distilled. Before I bought my first ph pen I read as much as I could. Some product manuals said to never store in distilled water. Some said to never rinse in distilled. Some said never try to measure distilled. There was never any consistency. The Etekcity manual doesn't say anything about distilled (while the Milwaukee did).

I'd stop exposing it to distilled water. I use tap water for rinsing, just hold it under the faucet for 2-3 seconds. My tap is about 650ppm in case you're worried about the quality of your water.

Again, let it dry to see if that helps. You might be keeping yours too wet (letting it soak in solo cups).

 

[crawlintbss]

Thanks. My bad didnt see you answered up above.

I dont store it in any water. When its done in use it sits out standing up on papertowel until next day then i cap and put with my stuff. Still standing up.

Thanks again

 

[explosive82]

http://www.amazon.com/Oakton-EcoTestr-Waterproof-Tester-Range/dp/B004G8PWAU/ref=lp_393271011_1_3?s=industrial&ie=UTF8&qid=1418460625&sr=1-3

had this for about 1 1/2 years works great

 

[BigEasy1]

http://www.amazon.com/Oakton-EcoTestr-Waterproof-Tester-Range/dp/B004G8PWAU/ref=lp_393271011_1_3?s=industrial&ie=UTF8&qid=1418460625&sr=1-3

had this for about 1 1/2 years works great

I have that one too and I'm pleased. Started out with the cheapo red one and it lasted for a couple years but this Oakton is much better built.

 

[Carolina Dream'n]

You can find a combo meter on eBay or Amazon cheap. Keep it in storing solution when not being used. Calibrate once a month.
If money isn't an issue, bluelab guardian are amazing. Their battery powered combo meter is good too.

 

[az2000]

I dont store it in any water. When its done in use it sits out standing up on papertowel until next day then i cap and put with my stuff. Still standing up.

I didn't realize you left it uncapped on a regular basis. I wouldn't do that. If you rinse then cap, that should keep it moist enough for 2 days. You don't really need to put drops of water in the cap as I suggested, that would be more for longer storage. And, as I said, using water as a storage solution (even just rinse and cap) leads to film which affects the pen's performance. The cleaner solution removes those proteins. The KCl storage solution reduces their formation.

It's probably the drying out between uses that makes it unstable. When I let mine dry out (intentionally, after it got too wet and became unstable), it took a couple calibrations before it settled down.

 

[crawlintbss]

Ahhh Thanks for the information AZ! You are a great help! Im usually mixing gallons every other day so it isnt sitting to long without being in use.

Will keep all this info as great knowledge, and ill give this one another try again. It seemed to work great its first month then once i noticed my soil was only at 5.8 i knew it wasnt in calibration anymore.