New RO filter and PH question.

Not sure about just RO but with RO/DI pH is difficult to test accurately. I'd let it sit and then retest it. But with those low GH and KH numbers I'd just ignore the pH. It should be within a couple tenths of 7 after stabilizing/equalizing.

Do you know the TDS?

EDIT: The pH testing problem with pure water is it's low buffering capacity and how the pH test chemicals work. Even pH probes don't work well in this case.

SteveU

GTR said:

Not sure about just RO but with RO/DI pH is difficult to test accurately. I'd let it sit and then retest it. But with those low GH and KH numbers I'd just ignore the pH. It should be within a couple tenths of 7 after stabilizing/equalizing.

Do you know the TDS?

SteveU

Click to expand...

Nope I'm waiting on a TDS meter to arrive. It does taste fine though.

Craig

I have the same issue with my RO water, i dont remember what it tested at now, but it was alot higher than i expected. I just pretty much ignore it though like GTR said. I use 1/3 tap and 2/3rds RO water, and i havent tested my water in a LONG time...everything is thriving though

Thanks, after Googling around I see that PH can very alot depending on the intake water and the RO system.

I have tested the water after sitting out for a couple of hours and the color is lighter then the first test so the PH will probably level out somewhere in the 7.2 vacinity.

Hope to get my TDS meter in soon so I can check the quality of the water prior and after the filter.

This is for my shrimp tank and for drinking water so all should be good.

Craig

Don't test your PH on RO because it is very unstable. You will have to add something like Equilibrium to stabalize the water first. I add the RO water to my tank and take readings an hour after. I only do 20% water changes and let the RO run into the tank (takes several hours to fill) by refilling slow, I am not shocking the fish.

Figured I would update as I jsut picked up my TDS Meter. A dual HM inline unit for my system.

TDS out of Tap - 122ppm
TDS out of RO - 011ppm

Looks like it is working just fine.

Craig