PH too high

[PrettyFishies]

After battling low PH and finally giving up and letting it run it's course, my PH is now above 8.5 sometimes as high as 8.8.

I tested my RODI water with a meter and got over 11! Now, I'm told that testing RO water can be inaccurate. My change mix is testing around 8.4.

I have to test my alk but in the meantime, what can be some other causes?

[Sniperhank]

Ph changes as the day goes by. Don't chase 'perfect number' ph. Just keep up with water changes and it'll be fine in the long run.

[uh.oh...]

Yes, testing pH is looking for dissolved salts. So, if your rodi unit is working, you shouldn't have any salts. So, inaccurate test. Additionally, some tests include things like borate, which also don't give an accurate measure. Test your salt water just before you add it back to your tank after a water change instead, see if your mix is mixing up right. light reading

[mrvincent]

RODI water is usually at PH 6-6.5. You must test it with electronic meter, liquid tests will give innacurate testings.

To test RODI unit u need a TDS meter.

What's your alk?

[PrettyFishies]

TDS is 0 electric
PH meter says 10 electric
Alk is 12 Hanna

Mix water is 8.5

Do resin and the cleanliness of the filter impact PH? I threw out my color-changed resin and kept the fresh. Seemed to bring it down a bit

[mrvincent]

Originally Posted by PrettyFishies

TDS is 0 electric
PH meter says 10 electric
Alk is 12 Hanna

Mix water is 8.5

Do resin and the cleanliness of the filter impact PH? I threw out my color-changed resin and kept the fresh. Seemed to bring it down a bit

How can the alk be 12 and the TDS at zero ?...

RODI water should be 0 TDS, 0 alk, and Ph around 6-7.

[PrettyFishies]

Sorry. I meant alk for the tank. I didn't test the ro.

Ultimately, I only want to know why the PH of my RO water is so high and what are the potential contributing factors.

[mrvincent]

If the TDS are at zero, then you have a false reading...

Drink it, you'll see it doesn't taste anything... My RODI water sometime test 4, sometime 11 with my cheap PH meter...

[Piercy87]

You're getting ph bounce. Alkalinity is a ph buffer and unless it's above 80 ppm then you'll you'll never have a true ph reading one minute it could be 6 then 11 the next.

[mrvincent]

Originally Posted by Piercy87

You're getting ph bounce. Alkalinity is a ph buffer and unless it's above 80 ppm then you'll you'll never have a true ph reading one minute it could be 6 then 11 the next.

Yeah, RODI water have no buffer.