Ro System Vs PH

[crxin]

So I just hooked up my 4 stage RO system, and i wanted to perform some more tests before i just started to do water changes with that system. I mixed up a glass of ro water, with the salt i am using (reefcrystals) to right around 1.025 sg. I tested the ph of the glass and it seems to be around 7.4 or so, and my tank is aroune 8.4 or 8.2. How can i fix this?

 

[Mreefer]

what's the tds of the ro water and its pH alone with no salt.

 

[crxin]

the tds is suppose to be 0 coming out of the system, so it claims, but i do not have a tds meter to verify. The ph of the system is about 6.6 or so, it is kinda hard to tell...

 

[juiceguy]

tds should be 0 and ph of R/O water is usually in the 6 range. was your ph reading from freshly mixed batch of water or was it mixed and aerated from the day before?

 

[crxin]

freshly mixed, i never arrate the water though, should i be?

 

[juiceguy]

fresh R/O water is high in CO2 and that is the reason your ph is low. mix your salt and run at least a powerhead over night and re-check the following day. your fresh mix of salt needs time to blend with the water and blow off any CO2.

 

[crxin]

i was just testing this with a glass of mixed saltwater for now, before i went to a higher level of a water change or something. So if i let it sit overnight and stir it a lot (for this test) it should come back up?