Dramatic pH drop in filtered H2O?

[khyberkitsune]

I picked up a fresh Brita water filter yesterday, and have been using it to do some minor water treatment. I noticed something - the pH drops from about 8.5 to a near-perfect ~5.8 just going through the filter.

Does anybody else experience this? I typically just use straight tap but I'm willing to roll with a water change, and at least filter it before adding nutes. Looks like if this keeps doing what it does, all I have to do is add nutes after filtering, no pH down required!

khyberkitsune Reviewed by khyberkitsune on 05-19-2010. Dramatic pH drop in filtered H2O? I picked up a fresh Brita water filter yesterday, and have been using it to do some minor water treatment. I noticed something - the pH drops from about 8.5 to a near-perfect ~5.8 just going through the filter. Does anybody else experience this? I typically just use straight tap but I'm willing to roll with a water change, and at least filter it before adding nutes. Looks like if this keeps doing what it does, all I have to do is add nutes after filtering, no pH down required! Rating: 5

[Daddynobucks]

That seems like a big drop,and to 5.8 seems even stranger.You are using a meter right? not some test papar strips. those papers are so EASILY contaminated.

What was your last filter puting out for Ph? Let us know what it does after 20-30 gal of use.

Daddy

[khyberkitsune]

That seems like a big drop,and to 5.8 seems even stranger.You are using a meter right? not some test papar strips. those papers are so EASILY contaminated.

What was your last filter puting out for Ph? Let us know what it does after 20-30 gal of use.

Daddy

I use liquid reagents for pH testing. I don't use paper, and meters require constant calibration.

I wasn't using ANY filter, at all, ever, until now.

[cigarettes42]

i agree with daddy. its your testing equipment. get a good ph meter and ditch the liquid. ph meters will last a long time if you take care of it. i have a hanna (which i dont like) that does the job and i only had to recalibrate it once in 2 years. the calibration solution is cheap too. probably $3 for both ph4 and ph7 calibration fluid. temperature of water can screw up test strip or liquids because they dont have a temp compensation built into it.

[LOC NAR on probation]

Agreed.

Bro uses a britta and it only drops his tap water .02 or so.

I have 2 R/O filters and the water is almost the same after. 7.0 before and 6.8 after.

I have a hanna combo that needs the ph probe replaced for the scound time but 6 years old. Now I use a cheap milwalkie but they work very well and last as long as you don't drop them in water. And I know when it needs calibrating by always checking the R/O, it never changes.

[khyberkitsune]

So I broke out the rest of my chemistry set and did an analysis.

Brita's special filtration resin removes calcium and magnesium ions and replaces them with H+ hydrogen ions, resulting in the acidic pH of filtered water. It does not remove carbonates, which are now present in excess as HCO3-. If I were to boil this, my pH would go from 5.8 to a likely ~10 because the CO2 gas would split, leaving OH- ions in place which would cause the rise in pH.

[Daddynobucks]

that makes perfect sence

one ques. is the resin an ION exchange resin and does it use Na in the exchange?

Daddy

[khyberkitsune]

that makes perfect sence

one ques. is the resin an ION exchange resin and does it use Na in the exchange?

Daddy

Yes, it is an ion-exchange resin, but given that it also works as a metals filter, I don't think it's using Na. Besides, typical purified Na is reactive with water.

[Daddynobucks]

yep pure Na is a no no with H2O, in the resin its bonded with ?? di-alkyl?? what evers. but some Na does get loose as a salt of some type and can screw with K uptake. not that Britta uses this type resin
if you have a GOOD chemistry set you can check for Na in the filtered water.

I think I'll pick one up and do some comparing, I now use a hydro-logic Cl/chloramine filter

Daddy

[khyberkitsune]

yep pure Na is a no no with H2O, in the resin its bonded with ?? di-alkyl?? what evers. but some Na does get loose as a salt of some type and can screw with K uptake. not that Britta uses this type resin
if you have a GOOD chemistry set you can check for Na in the filtered water.

I think I'll pick one up and do some comparing, I now use a hydro-logic Cl/chloramine filter

Daddy

Practically nil Na in the water after running through the filter, going by taste alone.