Lf calibration fluid for ph prob
 

As it says

I have a bottle of 4.0pH that I no longer use (my pH pen got busted). If you want, you can have it.

The Manuel says to use a ph of 7.0 and 10.0 to calibrate I'm new to the apex so not sure if it would work but thank u for the reply

Since the manual says that, you should follow it I guess. You can grab small packs of powders from LFS that you have to mix with specific amount of RO/DI water.

Most stores carry the 7 & 10 calibration solutions for only a couple bucks. If you have a ph test kit you could make your own solutions but its a pita.

Or better yet go to a hydroponic store and grab a bottle of each fluid for under $5/bottle. Much cheaper than the one use packages they sell at LFS

Now that I no most lfs carry the powders ill pick some up thanks

I've never seen a powder, I've only seen it in little bottles or foil packets.

The small foil packets has the powder that you have to mix with prescribed about of water :mrgreen:

I've only ever used the DA bottles (7/10) or the Hanna packets with liquid solutions (4/7/10)..I'm aware of the powered stuff you can get from hydroponic shops but have never seen it in a SW store. Meh