Newbie, PH questions

Hello all,

As you can see, I am a new poster here. I have been digesting everything on this terrific site since I discovered it a couple of months ago. I have read all of the FAQ’s and the sticky’s and I appreciate all of the members who are very generous in sharing their considerable experience.

I am getting tooled up for my first project. I will try to limit this post to one topic: PH

I know that PH is important and I want to be in control of it. I don’t mind investing in an electronic device but I am put off by the constant maintenance that they all need such as calibration, buying calibration solutions, limited component life (electrodes) and that sort of thing.
For growing in soil, would it be a serious mistake to go into this relying on a PH test tube kit? I picked up an API kit at Walmart that tests between 6.0 and 7.6. According to this thing, my tap water is slightly alkaline. I tested some distilled water and it appears to be around 6.0 (does this sound right?). I know that this does not give me digital information but I am wondering if it can be considered accurate enough , as I said, for growing in soil.

I plan to use fresh Fox Farms Ocean Forest/perlite/vermiculite in a 75/20/5 mix so I think my soil should start out pretty neutral (comments?). I will be using the Fox Farms trio of liquid organic nutrients and following the FF recommended feeding schedule and using aged tap water.

A related question I have is what is the advantage of using PH up and PH down solutions instead of things like baking soda and distilled vinegar?

All replies will be sincerely appreciated.

you can test with the liquid test kits, they work.... maybe not as accurate or efficient as a digital one, but they get the job done.

i think ph up and down is allot more concentrated than baking soda or lemon... so you would have to use allot less.... i use usually less than a capfull of ph down to treat 30 litres of water!!!

Thanks for the reply Moby, I was beginning to feel like it was a really stupid question. I think I'll probably go with this kit for the first grow anyway and get the PH up and down just so I'll know what I have.

Get some dolomite lime, add it to you medium at about 1tbls per gal of medium...and leave the ph kit alone. No need to screw with ph in a peat based mix if you have lime in it.

Why complicate things? Peat tends to get acidic over time...so the lime will continue to buffer the ph to near 7.

Drink!

Thanks FJ, this is something I was not aware of. But I had not planned on PHing the medium at all, since I am starting with a neutral mix (assumed, because the Fox Farms soil is PH adjusted and the perlite and vermiculite are supposed to be neutral). The PH kit is to monitor the PH of my nutrients and water. I should be doing that, right?
I will add the dolomite lime as you suggest.

Father Jack said:

Get some dolomite lime, add it to you medium at about 1tbls per gal of medium...and leave the ph kit alone. No need to screw with ph in a peat based mix if you have lime in it.

Why complicate things? Peat tends to get acidic over time...so the lime will continue to buffer the ph to near 7.

Drink!

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Nice to know, so if I add 3 tablespoons? of dolomite lime into a 3 gallon container I wont have to worry about ph problems?

dzk said:

Thanks FJ, this is something I was not aware of. But I had not planned on PHing the medium at all, since I am starting with a neutral mix (assumed, because the Fox Farms soil is PH adjusted and the perlite and vermiculite are supposed to be neutral). The PH kit is to monitor the PH of my nutrients and water. I should be doing that, right?
I will add the dolomite lime as you suggest.

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If you have the lime in your mix....then ph'ing your nutes is not essential. The lime will act as a buffer. Growing in a peat based mix means your ph should be around 7....so thats what the lime will maintain.

Growgirl said:

Nice to know, so if I add 3 tablespoons? of dolomite lime into a 3 gallon container I wont have to worry about ph problems?

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Correct. Lots of folks wonder why they're plants start to look like shit halfway through flowering ina peat based mix. It's usually the peat breaking down and going acidic. Lots of companies are adding lime to the mix before packaging now...but it's better to be safe than sorry. I have never had a problem adding too much lime...only not enough.

Drink!

What can i use to see what the ph of my water is?

ѕψЫiмiиλ[Ł]™;369644 said:

What can i use to see what the ph of my water is?

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You can use anything that you would use to ph your nutes. I will be using the test tube kit mentioned above. It is sold in the aquarium supply section at Walmart and involves adding three drops of a testing solution to a test tube of whatever you are testing. Then you compare color to a chart. Not nearly as accurate as an electronic device but very inexpensive and easy to use, unless you are half color blind as I am. The range is limited too but should be adequate for water.

Father Jack said:

If you have the lime in your mix....then ph'ing your nutes is not essential. The lime will act as a buffer. Growing in a peat based mix means your ph should be around 7....so thats what the lime will maintain.




Correct. Lots of folks wonder why they're plants start to look like shit halfway through flowering ina peat based mix. It's usually the peat breaking down and going acidic. Lots of companies are adding lime to the mix before packaging now...but it's better to be safe than sorry. I have never had a problem adding too much lime...only not enough.

Drink!

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This is good information Father Jack. As much as I have read I have not picked up on this before. It really puts my mind at ease about this ph business. I would hate to have spent all of this money on lights, nutes and ventilation and blow it over ph.

You can also get some litmus paper for cheap at the pharmacy...it will give you ph results...but those the most easiest to read and judge.

A milwaukee ph pen can be had on ebay for about $22. It's not water proof...but pretty reliable.

Drink!

I'll check that out. It is less than replacement parts for some of the others. Although I don't feel the need as much as I did since I found out about the dolomite lime. Thanks again.

Glad to be helping. It's what the forums are about. We can all learn from each other.

Drink!

if the plants are already potted can you just add some lime to top of the soil and water over it? Will the watering get it down into the soil?

Yes you can. And to go a step further...try and work the lime into the top of the soil so it starts to do it's work quicker.

Drink!

you should check out this from Earl:
CC Hydro 101 by Earl - Cannabis Culture Forums

i have the same test kit you do from walmart. It works for me except it only reads between 6.0-7.6. I used concentrated lemon juice and it actually worked real good and cost 75 cents for 4 ounces, dropped my ph real quick. If you got a big rez just get some ph down though. I have a 20 gallon rez and will probably just get a big bottle of ph down soon

jbreeze said:

i have the same test kit you do from walmart. It works for me except it only reads between 6.0-7.6. I used concentrated lemon juice and it actually worked real good and cost 75 cents for 4 ounces, dropped my ph real quick. If you got a big rez just get some ph down though. I have a 20 gallon rez and will probably just get a big bottle of ph down soon

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Did you add it straight to the soil without diluting it?