Can't get my watering pH straight after adding CalMag.

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luiz9733

luiz9733

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Hi guys, as a new grower my struggle is with my watering pH after dissolving 1g of Calmag in a liter of tap water. My tap gives me a 7.2 pH and 30 ppm, after adding Calmag if bumps to 8.5pH and 124 ppm. Then I start adding drops of pH down solution (chloridric acid) until the pH reaches 6.5... everything looks fine for a few minutes until the pH begins to go up for no apparent reason. Usually it goes all the way up to 8 again, then I add more pH down bringing to 6.5 and it goes up again, etc... can't stabilize at 6.5! By adding that much acid I end up with a very high ppm (I guess the pH down solution adds particles to the water) and still not able to stabilize the watering pH on 6.5, what am I doing wrong here?

Thank you.
 
growsince79

growsince79

9,065
313
Hi guys, as a new grower my struggle is with my watering pH after dissolving 1g of Calmag in a liter of tap water. My tap gives me a 7.2 pH and 30 ppm, after adding Calmag if bumps to 8.5pH and 124 ppm. Then I start adding drops of pH down solution (chloridric acid) until the pH reaches 6.5... everything looks fine for a few minutes until the pH begins to go up for no apparent reason. Usually it goes all the way up to 8 again, then I add more pH down bringing to 6.5 and it goes up again, etc... can't stabilize at 6.5! By adding that much acid I end up with a very high ppm (I guess the pH down solution adds particles to the water) and still not able to stabilize the watering pH on 6.5, what am I doing wrong here?

Thank you.
What are you watering that you need to ph 125ppm? Probably doesn't matter in soil and if its hydro the nutes will bring the ph down.
 
growsince79

growsince79

9,065
313
Hi guys, as a new grower my struggle is with my watering pH after dissolving 1g of Calmag in a liter of tap water. My tap gives me a 7.2 pH and 30 ppm, after adding Calmag if bumps to 8.5pH and 124 ppm. Then I start adding drops of pH down solution (chloridric acid) until the pH reaches 6.5... everything looks fine for a few minutes until the pH begins to go up for no apparent reason. Usually it goes all the way up to 8 again, then I add more pH down bringing to 6.5 and it goes up again, etc... can't stabilize at 6.5! By adding that much acid I end up with a very high ppm (I guess the pH down solution adds particles to the water) and still not able to stabilize the watering pH on 6.5, what am I doing wrong here?

Thank you.
Something don't sound right. 125ppm should only need a few drops to bring it down. All the calmag I've used has been pretty neutral ph. What are you using to check ph? What type calmag and how does the ph of your calmag compare to the other kind?
 
luiz9733

luiz9733

25
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Something don't sound right. 125ppm should only need a few drops to bring it down. All the calmag I've used has been pretty neutral ph. What are you using to check ph? What type calmag and how does the ph of your calmag compare to the other kind?
It does come down easily, just won’t stay there for long. I used a calibrated ph pen and drops, both confirms that the ph goes back above 7.0 after a while. I can’t see how calmag can be neutral, it is always alkaline.
You're adding calmag first and letting it sit for a bit right?
Yes, mix well with water… let it rest for hours, remove the deposit powder from the bottom, pass thru a coffee filter then ph it down but after a while ph goes up again. Today I added drops until ph went all the way to 3.5 and a few hours later is already at 6.0 and rising.
 
luiz9733

luiz9733

25
3
I use FatCrystal Calmag and the pH down solution is a simple combination of distilled water plus Chloric acid. Prepared before watering the plants but can’t stabilize the ph by any means no mater how many drops of ph Dow I put in it. It always goes up after a few hours of rest.
 
KrazyDave

KrazyDave

10
3
Have you tried just pHing plain water? Maybe your pH meter is faulty? I'm just guessing now though, this has me stumped.
 
luiz9733

luiz9733

25
3
Have you tried just pHing plain water? Maybe your pH meter is faulty? I'm just guessing now though, this has me stumped.
I have not, will give it a try on plain water... but the meter is calibrated and I confirmed the situation with one of those pH drops... they all show the same.
 
growsince79

growsince79

9,065
313
I have not, will give it a try on plain water... but the meter is calibrated and I confirmed the situation with one of those pH drops... they all show the same.
Just tested GH calmag 7.6 @ 165ppm so slightly alkiline. Let sit 15min and add a few drops of FF ph down and it went to 6.5. 2 hrs later 6.6.
 
luiz9733

luiz9733

25
3
So I’m doing something very wrong here, maybe the fish tank ph down solution has something to do with it. I’ll give it a try on some lemon juice.
 
growsince79

growsince79

9,065
313
So I’m doing something very wrong here, maybe the fish tank ph down solution has something to do with it. I’ll give it a try on some lemon juice.
You could just add a few drops of nutes.
 
Aqua Man

Aqua Man

26,480
638
Ok get im just gonna blunt and ot bother looking those up.

Buy a bottle of calmag and get phosphoric acid PH down.


If using RO you must add an alkalinity buffer. I promise you your cal mad doesn't not and that's your issue.... you have NO alkalinity and that makes for a very very very unstable PH and high fluctuations.

You first clue is it tKes very little acid to lower the PH.
 
Edinburgh

Edinburgh

2,692
263
Add a bit of white vinegar to a 16oz cup of water stir and give plant go easy you can always repeat, baking soda will raise it same drill just go easy! I find this works much better than pH up/down.
 
Aqua Man

Aqua Man

26,480
638
Add a bit of white vinegar to a 16oz cup of water stir and give plant go easy you can always repeat, baking soda will raise it same drill just go easy! I find this works much better than pH up/down.
Please don't do this and no it absolutely doesn't. In soil you can but it absolutely isn't even needed to PH adjust your nutes for soil anyhow.
 
tobh

tobh

Supporter
4,194
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Please don't do this and no it absolutely doesn't. In soil you can but it absolutely isn't even needed to PH adjust your nutes for soil anyhow.
+1. Keep cooking supplies in the kitchen. Same with lemon juice. Get some proper buffers if you're going to be serious about growing. They're cheap and do exactly what one expects them to.
 
luiz9733

luiz9733

25
3
Just bought some hydroponics pH down phosphoric acid based solution and should arrive tomorrow, this should fix the issue according to the manufacturer of Calmag, apparently the fish tank stuff is not suitable for this. I’ll let you all know how this turned out. Thank you!
 
Saul.Goodman

Saul.Goodman

I just wet my plants...
Supporter
862
143
Just a note, my GH CalMag raises my PH by 1.0 when using 5ml/gal which is the "general recommendation".
 
Aqua Man

Aqua Man

26,480
638
OP please read carefully and if you have questions after let er rip.

Just saves me time in reposting info many times.

 

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