My ph meters keep showing different amounts and don't seem to respond to ph changes, but they always read the reference solutions correctly.

[Bantersaurus]

I bought two of these and I calibrated them using both the 250 mL powder and some reference solution I bought separately. They read the calibration solutions just fine, but then I dip them into what I'm testing and they're about 0.4 ph off. Then I add some ph up/down and their readings are usually within 0.2 ph of what it read originally or something way off.

Would it be better to use 7.0 reference solution instead of 4.0? They did read the 6.86 powder that was included within 0.05 ph of what it was supposed to be, so I'm not sure what's going on. I'm thinking it won't really matter as long as I use both and average it out to between 6 and 7 ph, but I'm not sure.

I've been scared to feed her anything after I had one feeding that was way off in ph, but I'm pretty sure she needs nutrients soon. It's about day 37 and I've barely used any nutrients in Happy Frog soil.

 

[Jimmythenugg]

I would start with some relaxing there, @Bantersaurus.

PH is probably the most important facet of the feed, but you appear to have a small intolerance in the metres; btw I (and most peeps here) have two the same but found them useless so binned them.

When are you testing the feed, is it right after mixing or do you let mix settle?
Simply by virtue of nutrients blending together takes a few minutes for any chemical changes to level out?

However, appreciate its not nothing, .4 is half a mark but if you apply that, you should still have flexibility of a margin of error...
Regarding the calibration, if I remember rightly they had an extra calibration level for extra precision..?!

 

[Bantersaurus]

I would start with some relaxing there, @Bantersaurus.

PH is probably the most important facet of the feed, but you appear to have a small intolerance in the metres; btw I (and most peeps here) have two the same but found them useless so binned them.

When are you testing the feed, is it right after mixing or do you let mix settle?
Simply by virtue of nutrients blending together takes a few minutes for any chemical changes to level out?

However, appreciate its not nothing, .4 is half a mark but if you apply that, you should still have flexibility of a margin of error...
Regarding the calibration, if I remember rightly they had an extra calibration level for extra precision..?!

I'm pretty relaxed. Just very thorough.

I prepared a gallon of feed, tested the ph, then let it sit overnight. I came back and tested it again. It was a reading a little high, so I added 2 - 4 drops of ph down, and then I tested it again. 2 - 4 drops in a gallon should've lowered it by more than 0.3 - 0.4, but that's where the average came out to be.

I ordered some 7 ph reference solution off of Amazon (already own some 4 ph solution). I figure, like you said, it won't be accurate, but I'll know that it likely is between 6 and 7, which should be sufficient for a soil grow. For future reference, how long should I wait after preparing the mixture I'll be feeding to test the ph?

 

[Jimmythenugg]

Personally, I leave mine for 30 mins. I grow in coco using BioB n a few other organic bits, but I measured everything before n after adding (by degrees when started) everything I use, so I don't have this prob anymore -

Btw I use lemon juice or bi carb for - & + respectively: some will say don't but I've never had an issue and saved a fortune (since my tap is 7.5 and with a full bloom load still runs at 5.5 so I'm happy, mostly ph- when i reuse veg run off to use in bloom so minimal 2 or 3 drops of lemon juice.

I'm normally broke to be honest and have managed a free work around for now, but if I had the cash I would invest the £70 or so for a blue lab meter almost certainly the only way to go, IF you can't eyeball it...

 

[Mustang92]

I'm not totally sure but I thought you needed two buffer solutions to calbirate meter, I think some people use 3 buffer solutions to calibrate.
I may of miss read your question but I calibrate with a 7ph then wait few minutes and do the 4ph calibrate.


Jimmythenugg , I've used lemon juice or vinegar for ph down and never had any problems other than a desire to eat fish and chips after.

p.s. wait for better answers than mine mate, my girlfriend says sometimes I'm a dumbass.

 

[thebombhaha]

Personally, I leave mine for 30 mins. I grow in coco using BioB n a few other organic bits, but I measured everything before n after adding (by degrees when started) everything I use, so I don't have this prob anymore -

Btw I use lemon juice or bi carb for - & + respectively: some will say don't but I've never had an issue and saved a fortune (since my tap is 7.5 and with a full bloom load still runs at 5.5 so I'm happy, mostly ph- when i reuse veg run off to use in bloom so minimal 2 or 3 drops of lemon juice.

I'm normally broke to be honest and have managed a free work around for now, but if I had the cash I would invest the £70 or so for a blue lab meter almost certainly the only way to go, IF you can't eyeball it...

My workaround this is a pH droplet tester kit. It's cheap as fuck and has served me well for my entire two grows thus far. I've never had a pH issue before because this goes by a color scheme. Highly recommend it.

I agree w you on bluelab. I would buy it too in the future to know my ppm. Like the dude said though pH is the most important. If your pH isn't the right level I imagine growing is hell. These cheap ebay pH and ppm meters I bought for my first run with photos were complete trash(couldn't even calibrate em) so I was forced to find a workaround there

 

[elcoloan]

I agree on investing in a real ph meter... but i have found several cheap ph meters that work as long as you don't bump them too much. I have had several yellow ones such as yours and other yellow ones which had to be calibrated with a small screwdriver... the screwdriver ones are better... the ones with auto calibration almost never stay calibrated. But looking around amazon i find only the ones that are like yours, that sucks. Don't buy more of those.

 

[Jimmythenugg]

I kept my drops n colour chart, but that goes up in single points, so risky but will keep you from making too much of a mistake if you feeling apprehensive about making a mistake.

Seems like every other 'run of the mill' problem with girls can be attributed to pH issues. Made me take extra care and getting stressed myself till I got a handle on it.
Hope it goes well OP, and you got soil so a little buffer won't hurt.

 

[Bantersaurus]

I have drops and tried them, but they don't work in murky/brown water (Recharge's base is molasses). The pen meter I bought said you could calibrate it with just one solution, but I do have a 7 ph solution coming, so I'll do 4 and 7 before my next feed.

I might buy a better ph meter in the future, but I don't really want to spend any more on this project. I just need to be reasonably sure that the water is between 6 - 7, after all.

 

[St. Tom]

hi pal if you dont want to mess around and worry buy a decent meter likes off a Hanna or a blulab I've bought all the cheaper ones as they work in a jam the ones with the screw in the back as long as you have some 7.0 buffer work ok but only last a little amount of time .also the 2 part calibration ones are more expensive and you normally do the 7.0 before the 4.0 also these are my 2 and I used the black one for a year with no issues and just lately bought the Hanna one