How much pH down per gallon?

UncleReemis

UncleReemis

Well-Known Member
I've got a 35 gallon DWC reservoir (30 gal because the whole bin isnt full) and I need to know how much pH down I should use per gallon if I wanted to lower it by 1. The brand of down is General Hydroponics. Thanks folks.
 
jhod58vw

jhod58vw

Well-Known Member
Not sure if there is a actual measurment. I always just and a few drops and check it. But your using alot more water then me.
 
marc88101

marc88101

Well-Known Member
Just do a little at a time, let it mix real good until its stable, then go from there..I hope you have a good Ph meter. Ph is one of the most important thing in growing. Don't go cheap on it! Blue lab guardian is the best! Keep your water temps down too...
 
UncleReemis

UncleReemis

Well-Known Member
marc88101 said:
Just do a little at a time, let it mix real good until its stable, then go from there..I hope you have a good Ph meter. Ph is one of the most important thing in growing. Don't go cheap on it! Blue lab guardian is the best! Keep your water temps down too...
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yeah, I've got a drop test kit at the moment. Ya know, test tube, chart, 5 drops of the stuff. It works fine. Thanks for the advice guys.
 
PJ Diaz

PJ Diaz

Well-Known Member
There's no set amount. It depends on the pH of your water, the hardness of your water, and the nute regiment you use. I have super hard tap water, and have to use close to 4mL/gallon. I plan to switch to RO water soon, which should solve that problem.
 
Illegal Smile

Illegal Smile

Well-Known Member
I stopped using pH adjustment entirely. Especially the GH just screws things up. I feel that if you use good nutes pH will take care of itself. Confession: I have not checked pH once in the last three grows.
 
billy4479

billy4479

Moderator
Illegal Smile said:
I stopped using pH adjustment entirely. Especially the GH just screws things up. I feel that if you use good nutes pH will take care of itself. Confession: I have not checked pH once in the last three grows.
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Indian Casino Owner: If you want to see your future, throw a prized item into the fire. [Bart throws something in the fire and it pops] Not a firecracker! Bart: Hey, I bought it off an Indian on your reservation. Indian Casino Owner: That's crazy talk! Bart: No, it's true. Indian Casino Owner: No, that's my brother, Crazy Talk. We're all a little worried about him.
 
Hydrotech364

Hydrotech364

Well-Known Member
PJ Diaz said:
There's no set amount. It depends on the pH of your water, the hardness of your water, and the nute regiment you use. I have super hard tap water, and have to use close to 4mL/gallon. I plan to switch to RO water soon, which should solve that problem.
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In the summer the a/c runoff water is a low ppm and a consistent 7.0 PH.I always had good luck with it in DWC.Its 80F here in Texas today so I'll be running the air today.I learned the hard way that it is best to put your air pumps in a box with a HEPA filter.Whatever is in the air ends up in the nutrients, like a giant Bong.
 
cues

cues

Well-Known Member
There is no measure because pH isn't a linear measurement. pH4 is 10x as acid as pH5 an 100x as acid as pH6.
Take into account that our nutes, starting pH and aimed for pH are all different, let alone the concentration of pH adjusting acids and there is little chance of working out the amount needed other than by experience in our own situations.
 
Will2Grow

Will2Grow

New Member
Since no one seems to know the answer, the general rule is approximately 1.25 ml per gallon of water to lower the ph 1 point. If your starting ph is more or less than 1 point away from your desired ph you will need to adjust the amount of ph down. Hope this helps.
 
Purpsmagurps

Purpsmagurps

Well-Known Member
Will2Grow said:
Since no one seems to know the answer, the general rule is approximately 1.25 ml per gallon of water to lower the ph 1 point. If your starting ph is more or less than 1 point away from your desired ph you will need to adjust the amount of ph down. Hope this helps.
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way to revive a 2013 post. but you are wrong it changes depending on your ppms. 1 tsp of ph adjuster will do more in lower ppms. it takes more in higher ppms to get the same ph adjustment.
 
Herb & Suds

Herb & Suds

Well-Known Member
Will2Grow said:
Since no one seems to know the answer, the general rule is approximately 1.25 ml per gallon of water to lower the ph 1 point. If your starting ph is more or less than 1 point away from your desired ph you will need to adjust the amount of ph down. Hope this helps.
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This is inaccurate water hardness plays a huge role in changing ph
Your theory may work on RO water but I'm skeptical
 
A

Aqua Man

Well-Known Member
Purpsmagurps said:
way to revive a 2013 post. but you are wrong it changes depending on your ppms. 1 tsp of ph adjuster will do more in lower ppms. it takes more in higher ppms to get the same ph adjustment.
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You can't go off ppm. It depends on the makeup of the ppm. Specifically carbonates as they provide the buffer.

There is NO answer unless you know the carbonate hardness of your water.

As others said add small amounts and check ph. Over time you will get a feel for your water.

And RO water has no buffer so it will shift drastically so it needs to be reconstituted
 
Will2Grow

Will2Grow

New Member
You guys are trying to be chemistry majors. 1 ml per gallon is a small amount. You have to use some simple mathematics. If you need to adjust your ph only half a point then use half the recommended ph down. approximately .6 ml per gallon. As I said it is a general rule that should get you close to the correct ph you are looking for but it is not the end all be all for ph adjustment, you have to be aware of your particular water requirements and you may need more or less for you situation.
 
A

Aqua Man

Well-Known Member
Will2Grow said:
You guys are trying to be chemistry majors. 1 ml per gallon is a small amount. You have to use some simple mathematics. If you need to adjust your ph only half a point then use half the recommended ph down. approximately .6 ml per gallon. As I said it is a general rule that should get you close to the correct ph you are looking for but it is not the end all be all for ph adjustment, you have to be aware of your particular water requirements and you may need more or less for you situation.
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So what your saying is the same as everyone else. Add a small amount and measure ph. Kk thanks.

As for the chemistry lesson. Take a gal of tap and a gallon of RO and do as you suggested. I mean it's nothing more than what should be basic knowledge in hydro
 
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H

hotdogmd

Member
Will2Grow said:
You guys are trying to be chemistry majors. 1 ml per gallon is a small amount. You have to use some simple mathematics. If you need to adjust your ph only half a point then use half the recommended ph down. approximately .6 ml per gallon. As I said it is a general rule that should get you close to the correct ph you are looking for but it is not the end all be all for ph adjustment, you have to be aware of your particular water requirements and you may need more or less for you situation.
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I just added .8ml to my one gallon nute RO water 6.6 ph. It went all the way down to 4.5 ph.
 
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