water changes and pH

[stgla]

New batches of sea water I make seem to have high pH (over 9, based on pinpoint monitor), compared to the tank level of 8.1. If the salinity and temp match, should I try to lower the pH of hte new water before adding to the tank (e.g. by adding some vinegar)?

[TekCat]

Wow, that's pretty high for freshly mixed salt. What kind of salt are you using? How old is it? What's TDS reading on your fresh water?

[mikenpam]

The answer is yes to attempt to match pH. The question would be why is your mix so high. Most salt mixes at around 8 from information I have read. I have used IO and Oceanic and both mixed right at 8 when salinity was 1.025.

[stgla]

old mix. do you think something got into it?

[TekCat]

something could get into it, or got out... never know.

[Scuba Oz]

I would get a batch of new salt and check it out. I have never seen a PH that high after a mix

[bertoni]

My salt mixes up to a high pH as well. After a bit of aeration, the pH is fine, though. Another brand of salt might be better if this is an issue for you.