R/O and Ph

[Gangaman]

is it normal for Ph to drop after putting water through an R/O filter??? This water is coming from a well and has a slightly low (6.7) Ph out of the tap but out of the R/O filter it's 5.6 or lower, this seems strange to me.

 

[Animal Chin]

It's normal that my RO is lower than my tap but I'm just curious what's the ppms of the well water?

 

[Gangaman]

i don't know, i've just moved in and i haven't had a water test done yet. icancansay it tastes metallic to me, just a bit. will that make a difference?? higher ppm = lower Ph of R/O'd water??

 

[bigdaddyg8]

is it normal for Ph to drop after putting water through an R/O filter??? This water is coming from a well and has a slightly low (6.7) Ph out of the tap but out of the R/O filter it's 5.6 or lower, this seems strange to me.

doesn't a RO filter pretty much strip the ppm,s and the PH to zero or near to it ?

 

[midwestdensies]

supposed to or be close. Id suggest a tds ppm ec pen to see what ppms are as well as starting ppms.

 

[Gangaman]

when you say it should be close do you mean my before/after Ph reading.and yeah Bigdaddy itd would seem that way to me to but that is def not whats happening

 

[midwestdensies]

Sorry meant supposed to be close to 0 or less than 70 ppms ideally

 

[sedate]

is it normal for Ph to drop after putting water through an R/O filter??? This water is coming from a well and has a slightly low (6.7) Ph out of the tap but out of the R/O filter it's 5.6 or lower, this seems strange to me.

1) How much water have you pumped through the filter?

2) No that doesn't sound right. RO water is really hard to get a pH level for and usually pH meters float around 7 - 8ish depending on the meter - and doesn't get nailed to a specific pH until the nutes and buffer solution is added.

 

[leadsled]

Do you use c02? Is your res is in the room with c02?

ph will be lower if there is c02 present in the water.

 

[Toker Ace]

Squiggly knows what's up with the RO deal and pH. Maybe he'll chime in but I do know that a RO setup filters out a high percentage of the dissolved solids but not all. By design, RO cannot really "purify" water because you can always slice the pie again theoretically. I think you should see a 90% reduction (10% left?) in TDS.

 

[squiggly]

Squiggly knows what's up with the RO deal and pH. Maybe he'll chime in but I do know that a RO setup filters out a high percentage of the dissolved solids but not all. By design, RO cannot really "purify" water because you can always slice the pie again theoretically. I think you should see a 90% reduction (10% left?) in TDS.

The analogy of always being able to "slice the pie" again is precisely correct. The "reaction" here follows an equilibrium constant which is biased heavily towards one side, but not ALL the way. There are essentially two types of processes--those that go to completion, and those which obey equilibrium (as in RO filters).

For instance, dissolution follows an equilibrium--whereas combustion or detonation goes to completion (in a general case).

To bring this back to a cannabis related process--when we do oil extractions, there are those of us who "clean up" the crude extract by doing what is known as a water/brine wash. The first wash takes out about 50% of water-soluble contaminants, the 2nd wash (with the same volume) takes out 50% of what was left--and so on and so on.

For this reason it is often better to do two 250mL washes versus one 500mL wash. The RO device is balanced around a similar function (and they will have maximized efficiency). You should look, in the best case, for about a 98% reduction in TDS. You can do better than this, but your input water needs to be very clean already.

A way to look at this a bit clearer is to imagine you're trying to dissolve 25 grams of table salt into 10mL of water. What you'll have is a bunch of wet salt. If you slowly bring the level of water up the salt will fully dissolve once you've got enough solvent capacity (or "spaces") for the ions to fit.

If, however, you take the same 25 grams of salt--and throw it into a lake. It will appear to instantaneously dissolve.

Equilibrium depends not only on products, but also the relative amounts of reactants. If there is a generous excess of one reactant--the reaction will appear to go to completion.

As for the pH dropping yes, this is normal--and I would remind you that pH is temperature dependent.

At room temp (25C) you should be seeing a pH of between 6 and 7. If its warmer than that, you will see the pH drop. A pH of 5.7 is not totally uncharacteristic for water, but it does warrant further investigation. Have you looked into having your water tested? 5.7 is generally the lower cutoff for pure water.

It's also important to realize that the way pH is both conceptualized and tested in the general public is not really indicative of its true properties and function. pH is insanely more complicated than most people and instruments suggest. A pH pen is your best friend in this regard, but at the end of the day it is a flawed measurement. Ions of any type severely affect the measurement, whereas a total absence of ions would make the measurement impossible (because a current cannot flow through 100% pure water).

If you go the testing route I recommend you send in both a tap sample and a sample post filter. There could be some substances that your filter isn't catching that will drop the pH.

If you have a reasonably sensitive pH pen and some scientific know how. You could perform a titration on your sample to determine if there's any buffering behavior or any acid to be neutralized which is left over post filter--beyond that your best bet is a testing facility or just grinning a bearing it and breaking out the pH up.

 

[Gangaman]

Squiggly, you're the man, thanx for the science, I needed that :) I get what you're saying to me and a water test is the next step (thanx for the suggestion of two samples, wouldn't have thought of that), and for the ladies I do just break out the 'ol Ph up and got no worries, but all this testing has got me questioning my family's drinking water. Do you know anything about magnets and water?? I have been putting a small stack of rare earth magnets (north pole) for about 48 hrs and that gets the metallic taste out and the Ph up to about 7.2 which I feel is more suitable for drinking but I don't really know, thoughts???

 

[squiggly]

Squiggly, you're the man, thanx for the science, I needed that :) I get what you're saying to me and a water test is the next step (thanx for the suggestion of two samples, wouldn't have thought of that), and for the ladies I do just break out the 'ol Ph up and got no worries, but all this testing has got me questioning my family's drinking water. Do you know anything about magnets and water?? I have been putting a small stack of rare earth magnets (north pole) for about 48 hrs and that gets the metallic taste out and the Ph up to about 7.2 which I feel is more suitable for drinking but I don't really know, thoughts???

My thoughts are that most if not all drinking water in this country is total shit--and you should have your family drinking RO/UV filtered water either from a costly setup at home or a reliable local supplier.

It's gone beyond the point of legitimacy. You don't get just H2O anymore. Not even close.

Hell the magnet, if anything, would take out the stuff that isn't harmful. All of the shitty stuff will remain.

It really is to the point that you have to question even the quality of the RO water you can get from suppliers. Your public water supplier is a far cry from that in nearly all cases in the US.

Its a really shit situation we're in.

For instance, my water supply has some kind of buffer in it (who the fuck knows what--a water test didn't turn it up, but my analysis shows clearly that its buffered). No info on this from the water company, nothing.

Just a chemist going what the fuck as he goes to the store to buy water.

Beyond that, I'm in the lab and I know the shit that goes down the drain. Lol.

 

[PButter]

I have been drinking and using filtered well water and RO for a few years now and when I go to town, I can't stand the taste and smells that come off town water. Public water is certainly in a sad state.
PB

 

[woodsmaneh]

That's not out of whack, most ro is around 6 give or take a bit.

RO water is not the best for you as it contains nothing and our body get some important things in water. I hope your taking some vitamins. Recent research has raised concerns about people using just RO.

Just Google this and you will see ...
is reverse osmosis water safe to drink