PH measurements keep changing during testing?

[dooxy]

Hey

I have done some digging but can't find the response to my question. Perhaps my English is not good enough to work the algorithm in my favor.

Every time i take a PH test with my pen (that i calibrate often), I will get different readings. i take some water out of my bucket, and i test it and it say PH of 6.2. Then after a few second it start drop down to let say 4.9. I adjust it with some PH up to around 6.3-6.5 since i know my plant always drop a point daily. Yet when i re-measure the PH fluctuate during testing.

I have read that it could be acid rain, the issue is i don't have a EC/PPM meter yet. So i just do water changes and try to wing it. I notice 1/4 of my leaves are turning yellow with some of the tips are brown. smaller leaves are also dying around the lower part of the plants. The buds are getting there, the white hairs are growing crazy. So i think am getting there, the buds have not yet gotten fatten.

So yeah am i taking the measurements wrong perhaps? or could it be an obvious issue going on there?

 

[Chris Scorpio]

Pics are always good to see how a plant is progressing or depressing


Once you place your pH pen in water, to the recommended hight per the instructions, it Should take a minute or so to find the actual pH. If it continues to move up and down it could be faulty
Try testing it on white vinegar. It has a pH if 2.4, if keeps fluctuateing it's a bad pen

You say it's rain water, not sure how acid rain would effect it, if that really exists....lol

I'd get a ppm meter, helps determine what's in your water as well as nute levels in runnoff


Good lucj

 

[Scientific]

We're taught that pure water has a pH of 7, but it's really not that simple.

Pure water has no chemicals in it that resist changes in pH ("buffers"), so its pH can change just by pouring it into a container, which mixes in air. (Measure the pH of a glass of water while you blow into it with a straw to see what I mean. The CO2 in your breath makes carbonic acid which lowers the pH a lot, and very quickly.) This is an important concept to grasp and remember.

Add to that an old pH probe that has a coating of stuff on its delicate glass probe, and possibly a probe tip that hasn't been stored in storage solution or has even been stored dry (shudder) so its ion balance is way off and you have readings that are wrong, hard to repeat, take too long to stabilize...

Learn about the subtleties of pH and pH measurement and how to properly use and maintain your instruments.

Happily PPM meters just measure the electric current between two electrodes, so they're much less fussy, but even they must be kept clean and should be calibrated in 1000 PPM NaCl solution periodically.

 

[dooxy]

Once you place your pH pen in water, to the recommended hight per the instructions, it Should take a minute or so to find the actual pH. If it continues to move up and down it could be faulty
Try testing it on white vinegar. It has a pH if 2.4, if keeps fluctuateing it's a bad pen

You say it's rain water, not sure how acid rain would effect it, if that really exists....lol

I have testing fluid and storage fluid that are at PH 7, they are sowing correct every time. Acid raid is something that happen i the wild from humans interfering with the plant. We over feed our eco system with nutrient turning rain water acidic. So it actually destroy part of our planet. The same can happen in a DWC if you use to much nutrient. I use about 50% of the recommendations. This could be an issue why my PH drops all the time.


I'd get a ppm meter, helps determine what's in your water as well as nute levels in runnoff


Good lucj[/QUOTE]

We're taught that pure water has a pH of 7, but it's really not that simple.

Pure water has no chemicals in it that resist changes in pH ("buffers"), so its pH can change just by pouring it into a container, which mixes in air. (Measure the pH of a glass of water while you blow into it with a straw to see what I mean. The CO2 in your breath makes carbonic acid which lowers the pH a lot, and very quickly.) This is an important concept to grasp and remember.

Add to that an old pH probe that has a coating of stuff on its delicate glass probe, and possibly a probe tip that hasn't been stored in storage solution or has even been stored dry (shudder) so its ion balance is way off and you have readings that are wrong, hard to repeat, take too long to stabilize...

Learn about the subtleties of pH and pH measurement and how to properly use and maintain your instruments.

Happily PPM meters just measure the electric current between two electrodes, so they're much less fussy, but even they must be kept clean and should be calibrated in 1000 PPM NaCl solution periodically.

I have read my meter manual and am calibrating it every 2 weeks and store it in a special solution in the cap. I normally take out a glass jaw and test from that. Since the system has the stones creating Co2, as you said it bubbles that part i have figure out.


Here is some picture of my plant turning more shit by the day. It has yellow leaves all ever with brown burnt spots. Even the buds with their small leaves are sowing signs of this burn. I now do water changes every 5 days. And thinning of doing water change every 2 days to adjust of the constant PH drop. I Ph my water 2 times a day with UP since it always hit down to 4.5 PH every time i check.

 

[Scientific]

Try testing it on white vinegar.

The fussy lab purist in me thinks it would be better to test the probe in a calibration solution formulated for that purpose. You can use pH 4.01 solution if you want a standard to use at the acid end of the scale. General Hydroponics makes one that you can buy on Amazon.

Acid raid is something that happen i the wild from humans interfering with the plant. We over feed our eco system with nutrient turning rain water acidic. So it actually destroy part of our planet.

My understanding is that most of the acidification of rainwater is caused by sulfur emissions from coal-filed power plants causing the formation of sulfuric acid in the atmosphere...

 

[Calvados]

I assume you use PH up and Down. I mix up my neuts 10 litres at a time. I stir after adding and I move the pen back and forth until I get a stable reading. If the PH adjuster isn't fully diluted, the readings can bounce around wildly. Make sure it's fully diluted. I know my tap water is normally around 7.3 so I also run the pen under the tap to double check.

 

[Calvados]

Here is some picture of my plant turning more shit by the day. It has yellow leaves all ever with brown burnt spots. Even the buds with their small leaves are sowing signs of this burn. I now do water changes every 5 days. And thinning of doing water change every 2 days to adjust of the constant PH drop. I Ph my water 2 times a day with UP since it always hit down to 4.5 PH every time i check.

Looks like you are overdosing on something. What exactly is your grow medium? Have you tried flushing? What’s your neut schedule?

 

[Scientific]

<edit: removed cuz I misunderstood >

 

[Calvados]

<edit: removed cuz I misunderstood >

No bros. The guy who is having the problem.

 

[Scientific]

No bros. The guy who is having the problem.

Too often I am the guy who is having the problem.

 

[dooxy]

my bucket fits only 20 L 5 gallons, but i only use about 15L because that is right under the net pot. I always mix my nuts first, after that i take out about 1L/ 0.26 gallon, that i PH adjust with a few drops. Put it slowly back in so i don't get PH dust clouded in the water that i got told can hurt the nutrients.

My issue is that the PH is dropping daily i adjust it two times a day to around 6 to 6.5 to have some room for the plant to drink from before it hit below 5 in PH. For me it is just so spooky that sometimes i take a sample and it say 4.5 then i take a new one 1 min later and it can say 5 PH.

 

[Calvados]

my bucket fits only 20 L 5 gallons, but i only use about 15L because that is right under the net pot. I always mix my nuts first, after that i take out about 1L/ 0.26 gallon, that i PH adjust with a few drops. Put it slowly back in so i don't get PH dust clouded in the water that i got told can hurt the nutrients.

My issue is that the PH is dropping daily i adjust it two times a day to around 6 to 6.5 to have some room for the plant to drink from before it hit below 5 in PH. For me it is just so spooky that sometimes i take a sample and it say 4.5 then i take a new one 1 min later and it can say 5 PH.

Why don't you PH adjust your pre-mixed 20 liter bucket? It would be easier. What is left needs to be vigourously stirred to mix anything that might have seperated or sunk to the bottom of the bucket when you go to use it at a later time. If you aren't giving your neuts time to properly mix, that would explain your variances.

 

[dooxy]

Why don't you PH adjust your pre-mixed 20 liter bucket? It would be easier. What is left needs to be vigourously stirred to mix anything that might have seperated or sunk to the bottom of the bucket when you go to use it at a later time. If you aren't giving your neuts time to properly mix, that would explain your variances.

Sorry am not understanding you, i add water, add nuts, take some water out add some ph to it put it back in and test and it gives me the correct reading 100% of the time. the only time it is fluctuating is a few days after the water change, then the bucket is in the then then i have to keep adjusting it.

 

[Calvados]

Sorry am not understanding you, i add water, add nuts, take some water out add some ph to it put it back in and test and it gives me the correct reading 100% of the time. the only time it is fluctuating is a few days after the water change, then the bucket is in the then then i have to keep adjusting it.

Maybe a problem with language. What are you growing in (soil (what kind), hydro, coco)?

 

[pontiacman]

Looks like nute burn on those leaves. I had the same issue with a plant 3 weeks ago. I just fed with regular water for a week and she's doing better now. No new burn. Those leaves won't recover but all of the new growth should be nice and green. PH is a big deal.

 

[dooxy]

Maybe a problem with language. What are you growing in (soil (what kind), hydro, coco)?

Hydro dwc single buckets

Looks like nute burn on those leaves. I had the same issue with a plant 3 weeks ago. I just fed with regular water for a week and she's doing better now. No new burn. Those leaves won't recover but all of the new growth should be nice and green. PH is a big deal.

That could be a thing a combination of to high LOW ph and to strong nuts? I cut the one i use with 2/3 or sometimes 2/4 of the MFR recommendation i use ghe nutrients. Anyway i also think it could be part of a light burn i use a 450W Mars Hydro light at 18 inch away from the plant, according recomendation, i have now move the light about 20 inch from the top bud. The issue seems to have stopped.

Am not sure if i should remove the sick leaves at all. I think that can do more harm then good.