ph question

[RTV]

I've tested my PH and it is off the charts- test kit measures up to 8.6 and I am above that- this is true of both my main and qt tank- I've only used ro/di water from the lfs so, this confused me. I decided to test their water prior to my last pwc.... guess what???? It's off the charts also. I was hopeful that I could lower ph through pwc's but, if the water I'm using has the same problem, that won't help-

Any suggestions on how to bring the ph down to an acceptable level?

[tecwzrd]

More then likely your test kit is off or expired. I’d get another AP/red sea/ Salifert test kit or take it to the lfs to have them test your water.

[malkore]

I second testing the water with a new/different kit. I pretty much only trust SeaChem and Salifert for SW testing.

RO/DI water should test at or below 7.0pH if the RO membrane is still functional. The DI stage helps remove phosphates and organics.

Here's a way you can test though...what's the carbonate/Kh/alkalinity of the new RO water? RO water should be no more than 1dKh, ideally undetectable levels. if you read no Kh, but a high pH, its likely your kit is bad. if you have lots of Kh, then your RO water isn't worth buying because its as hard as tap water.

[RTV]

Kh in the tank is high (i don't remember the exact figure right this minute but, it measured high and I read where that and high ph went hand in hand) Also, i checked expiration on ph test kit and it is good til '08- of course it could just be a bad kit. I will bring a sample to the lfs this week for a meter reading- I used the kit on my fw tank and it seemed to work appropriately although its a high range kit and the fw tank ph is below its lowest measure. Conversely- i tested the SW tank with my FW kit- may have been a waste of time but, boredom and curiosity got the better of me- again - appeared to measure 8.8 or possibly higher. So my question is this...if they are using local tap water through their ro/di process, would that system adjust the ph? I know the tap water here is very hard.