adjusting PH with 0 ppm

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420Gator

420Gator

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how am i suppose to adjust water that doesnt have anything in it? seems like the ph is unstable, all over the place. Ive been adding like 50 ppm of tigerbloom to help stabalize before adding ph adjustments. is there a better way?? Im using RO which doesnt seem as bad as distilled but pissing me off when i add a drop of up and it goes down by 0.1 so i add two drops and it goes up 2.1
:mad0233:
 
CelticEBE

CelticEBE

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Ok I don't have tons of experience but I would say you are leaving out some key information here. How much water are you trying to ph? Do you have a pump recirculating the water? What kind of ph up and or down are you using?

I have found larger amounts are a little easier to deal with. When I do foliar feed I only mix up a liter of water and my RO water comes out at around 7. I prefer to bring it down to 6.3 for foliar feeding. I use AN ph up and down and it REALLY concentrated. I use a syringe and put a drop in a separate cup with some water in it and then draw back some of that solution with the syringe. Then I slowly add that solution til I hit my mark.

Hope that helps you a bit.
 
X

Xceptional

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man when i would just water my soiless plants i would have to fill a 5 gal bucket with ro and then litterly just dip my eye dropper into ph down or my very finger tip and that is all. usually it would still go to low so i would dump half back into my 50 gal ro res then add back another 2.5 gal and use the waters ph to raise it back up some. it's a bitch to adjust it with zero buffer. i'd say add like 200 ppm nute so there is something in the water (and it's something with ph buffering even if it is in low doses) and make your life easier lol.
 
X

Xceptional

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i have noticed that ph up from gh moves the ph wayyyyy less then ph down from gh so if you do buy some up once you go down (and you will go to far down) it's a little easier to use up to get it back where you want it. i always hated the idea of adding crap to the water and then adding even more crap to the water just to get the ph right
 
Seamaiden

Seamaiden

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how am i suppose to adjust water that doesnt have anything in it? seems like the ph is unstable, all over the place. Ive been adding like 50 ppm of tigerbloom to help stabalize before adding ph adjustments. is there a better way?? Im using RO which doesnt seem as bad as distilled but pissing me off when i add a drop of up and it goes down by 0.1 so i add two drops and it goes up 2.1
:mad0233:
First, let that RO water sit out for at least a day. I don't (yet) know why, but when it comes out of the unit it's a pretty low pH. Then it comes up to just under 7 (my experience/unit), usually stabilizing around 6.8. When it comes out it's as low as 4.8.

Second, what pH adjuster you're using may have something to do with it and I'm wondering how much you're mixing it in before adding to adjust more. It should not be dropping pH at all.

Third, try mixing in up to 50% tap water and see what happens before you try adjusting pH.

Fourth, adjust pH before you add nutes and see what happens.

Fifth, if you're trying to adjust very small amounts of water, then I suggest changing that up to doing a larger amount at once. This allows you finer control.
 
G

Gro

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be patient!!!!let your ro water sit overnight before mixing in nutes.after mixing wait another couple hours before adjusting.i even wait in betwween acidic/alkaline adjustments before adding more.over correcting can easily be avoided with patients.
 
X

Xceptional

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i have a float switch and a 50 gal res that stays full of RO water and will sit for days or sometimes even a week before i touch it and i see none of this as a benefit in my experience. weather it comes fresh from the ro or sat for a week my ph seems to be about the same. if you're ph is adjusting sitting out over night (uncovered?) maybe airborne sediments are landing in it or residue in your storage container are contaminating your ro water (contamination first but the word is really overkill) and adjusts your ph. idk just never worked that way for me and i've been through at least 1,000 gallons of RO water in the last 5 months.

regardless nothing will make it easier to adjust the ph where it does not swing one way or the other drastically but a buffer! if it's pure water and it sits for a year and is still pure water you wll still have that issue. this is why your flushing water needs less ph up/down solution to move 1 point then your water with say 800ppm nutrients needs. which may be double the amount or more.
 
B

boroboro

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I don't use RO water, but I seem to remember reading in several places that it's quite difficult to measure the PH accurately of pure RO water. IIRC, this is due to the very low alkalinity and conductivity of pure RO water.

The general conclusion is not to worry about it, since the PH will be determined by whatever buffers, nutes, additives, etc. are in the stuff you're adding the RO water to.

edit: spent a minute or two on a Google search, didn't find anything overwhelmingly conclusive, but here is a snippet on this subject:

Generally, you will find that the pH from a RO system reads around 6 to 6.5 if you measure the ph of reverse osmosis (RO) water directly. All it takes is a minute measure of additive or impurity to make a large value difference, although this might seem like a problem, this is not an issue of pH measurements of water which is pure and means very little, to be adding something with such a low pH to an aquarium reef. Carbon dioxide is the most influential element as it adjusts the pH to a region of six when left for a good amount of time while the pH is allowed to rise and reach its equilibrium. As it only takes a small additive to change the pH of pure water as it has an extremely low alkalinity that is a sure measure of how well water will resist the change of pH. As a result, it is easier to change the pH with an alkalinity that is lower. Since the alkalinity is so much, lower and will not affect the pH of an aquarium’s reef water. Therefore, adding low ph water to your aquarium’s reef water is not a concern, you will not be endangering the ecosystem you have already provided for you aquarium’s reef life or fish. Understanding that using a lower alkalinity of pH to your aquarium’s reef water should allow you more comfort in knowing the water of your aquarium’s reef is safe.
 
B

bobman

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Are u just trying to water them or feed them. If your just trying to give them some water I would not even worry about it. I grow in hempy and soil and when I just want to give them water I don't even worry about it and I have had no problem. If I am feeding with ro I just cut it with tap water, about a 3 to 8 or 3 to 9 ratio, depending on what ph you are shooting for. This way I more near my mark and do not have to use a shit load of up and worry about shooting right by my number. I would also recommend a tote and a bubbler and just mix more at a time and give your nutes 24 hours to settle. I usually mix 10-12 gallons. I am still playing with my ratio's but 8 to 9 gallons of ro with 2 to 3 gallons of tap get me pretty darn close to 6.0-6.3 I want for hempy.
 
X

Xceptional

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ALSO some nutes like Flora Nova DROP your ph into the 4's with just a few hundread ppm and others barely move it. the RO manufacture i got mine from stated right on their site that running water through RO will not adjust the PH so it should be the same at the tap or out the RO unless you have something in your TAP that adjusts the PH of the water that is being removed through RO.
 
E

ent

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When you're working with soil with a very low EC/TDS, then there isn't much of a point of pH'ing your water. At this point just about as soon as that water mixes with your soil, it will increase in EC/TDS and the pH will pretty much be what your soil is.

After a transplant and a pH'd watering i'll typically have about 7 days inbetween waterings. The first couple days the moisture within the soil will stay within range, but sometimes depending on your soil mix (dolomite, etc), the pH will adjust and get out of range as it is drying out. I might see a bit of leaf tip curl, but as soon as i water again, things will be resolved. Also once the roots take hold and you water less often this is no longer an issue.

Basically the point of the last paragraph was to some show anecdotal evidence as to the water absorbing with the soil and the pH and TDS/EC will fluctuate.

*edit- Water with distilled or R/O and test your run off. That'll let you know what is really going on.

Also, letting RO water sit will do nothing.
 
G

Gro

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Also, letting RO water sit will do nothing.

when ro is initially filtered,ph readings are much lower than they are after a period of stabilization.mixing nutes during this period causes false readings which leads to over correcting.a common mistake.

letting ro water sit insures a stable ph platform to start with which leads to much easier and accurate nute mixing:cool
 
E

ent

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i have a float switch and a 50 gal res that stays full of RO water and will sit for days or sometimes even a week before i touch it and i see none of this as a benefit in my experience. weather it comes fresh from the ro or sat for a week my ph seems to be about the same. if you're ph is adjusting sitting out over night (uncovered?) maybe airborne sediments are landing in it or residue in your storage container are contaminating your ro water (contamination first but the word is really overkill) and adjusts your ph. idk just never worked that way for me and i've been through at least 1,000 gallons of RO water in the last 5 months.

I agree with Xceptional. But I'm willing to hear why we may be wrong? Do you know what is happening to the water during this time? Just doesn't make sense to me.
 
G

Gro

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I agree with Xceptional. But I'm willing to hear why we may be wrong? Do you know what is happening to the water during this time? Just doesn't make sense to me.

i have a float switch and a 50 gal res that stays full of RO water and will sit for days or sometimes even a week before i touch it and i see none of this as a benefit in my experience. weather it comes fresh from the ro or sat for a week my ph seems to be about the same. if you're ph is adjusting sitting out over night (uncovered?) maybe airborne sediments are landing in it or residue in your storage container are contaminating your ro water (contamination first but the word is really overkill) and adjusts your ph. idk just never worked that way for me and i've been through at least 1,000 gallons of RO water in the last 5 months.

regardless nothing will make it easier to adjust the ph where it does not swing one way or the other drastically but a buffer! if it's pure water and it sits for a year and is still pure water you wll still have that issue. this is why your flushing water needs less ph up/down solution to move 1 point then your water with say 800ppm nutrients needs. which may be double the amount or more.

hey ent,i don't think you and exceptional are wrong.i am just saying that there is an initial stabilization period of ro water, in relation to it's ph,and using it after that point removes variables.that in and of itself makes it easier to work with.
to be honest i do not know,from a scientific standpoint,what is happening to/within the water.my evidence is strictly empirical.supported by feed back from other farmers.

sounds like i have the same ro set up as you X.an auto feed from my hydrologic to a 50g. fit with a float.and yes my drums have sealed lids.

i went out and drew a sample of the ro water that is sitting in the drum,....it tested 7.0 on the money.i also drew a sample directly from the filter output,....it tests right now at 4.8 and still may be dropping.try this my dudes and get back to me.i'd dig the feed back!!

i wasn't trying to imply it gets better with age,just a short rest before use.:afroweed:
 
S

Sirius

490
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If your water is pure, it should be around 7. If not than your RO machine needs new filters. I found this...

"The pH of pure water (H20) is 7 at 25oC, but when exposed to the carbon dioxide in the atmosphere this equilibrium results in a pH of approximately 5.2"

so i would assume you have high levels of CO2 in your room where your water is coming out of the filter and it is mixing in with the water, after it sits it returns to 7...
 
G

Gro

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hey Sirus,what's up?

my water goes to 7.0 after a day but initialy comes out much lower.no CO2 in the work area and holding drums are sealed.

have you tested your ro right when it is first filtered?
 
420Gator

420Gator

1,281
83
i was adjusting for straight water no nutrients. I just said fuck it if it changes this quick in the res no reason it wont change just as quickly in the soil and follow suit with the 1300ppm i dumped in there the night before. Glad to see a few posts with the same logic. Thanks for all the replies
 
S

Sirius

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mine comes out at 6.5-7... after awhile (like now i need a new filter) it is higher... i dont see what sitting will do other than evaporate chlorine.. but just as a general rule of thumb i always aerate everything... but there shouldnt be ANYTHING in the water if it is pure... there should be no alk or acid in the water am i mistaken?
 
Seamaiden

Seamaiden

Living dead girl
23,596
638
Reverse osmosis, even reverse osmosis with deionization, cannot and does not produce pure water. Only distillation can make that claim. It is very, very clean, but not pure.
i have a float switch and a 50 gal res that stays full of RO water and will sit for days or sometimes even a week before i touch it and i see none of this as a benefit in my experience. weather it comes fresh from the ro or sat for a week my ph seems to be about the same. if you're ph is adjusting sitting out over night (uncovered?) maybe airborne sediments are landing in it or residue in your storage container are contaminating your ro water (contamination first but the word is really overkill) and adjusts your ph. idk just never worked that way for me and i've been through at least 1,000 gallons of RO water in the last 5 months.

regardless nothing will make it easier to adjust the ph where it does not swing one way or the other drastically but a buffer! if it's pure water and it sits for a year and is still pure water you wll still have that issue. this is why your flushing water needs less ph up/down solution to move 1 point then your water with say 800ppm nutrients needs. which may be double the amount or more.
Hey X, don't we both have RO/DI units from Pure Water Club? My RO/DI water always comes up in pH as it sits out, like G,ro says. Never higher than a 6.8 so far, but that's fine for my uses.
hey Sirus,what's up?

my water goes to 7.0 after a day but initialy comes out much lower.no CO2 in the work area and holding drums are sealed.

have you tested your ro right when it is first filtered?
This is my experience and observation, and if my record-keeping skills are good enough for the likes of large public aquariums, then I think it's safe to say that they're good enough for Mary. I have considered a few answers as to why, but without other testing equipment it's all guessing.

First, I know that the minerals that make the source water both base and alkaline have been removed. I already know the parameters, in terms of pH, German (dKH, 9 degrees out of the tap) and general (GH, usually over 10 degrees out of the tap) hardness of my source water using a titration colorimetric test kit (which, with a little calculating along with pH can give a number for the CO2 dissolved in the sample). I can assure everyone that it changes significantly when passed through the RO/DI--stabilized at that 6.8 versus 7.4 to as high as 8.4 pH.

Second, that water, which in my case comes from a pretty deep well, has spent some time under pressure before coming very gently out the other end and I already know that agitation equals CO2/O2 exchange, as well as the fact that atmospheric CO2 can and will change the pH of water in this condition.

So, why do I see such a huge fluctuation in pH readings between newly filtered water and water that's been in my trash can for a day or six? <shrug> I don't know. I know it hits an equilibrium, but I cannot state unequivocally that it's CO2/O2 saturation, or that it's anything else. I just know what I observe.
 
E

ent

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Perhaps it is temperature as that does affect the concentration of hydrogen atoms, and as a result, pH.

*edit-
Site went down as I was posting. Temps only affect pH slightly. Could also be the disparity between the temp of the probe and water.
 
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