ph probe suspected

[jamal]

i have been fighting low ph issues but now i am not so sure its the water. i put some fresh ro water in a container and put the probe in and it read 9.38. that doesnt sound right. then i added salt and it kept going down and is currently at 7.87. the water is at 1.028 sg. when i added my ca and alk for the day earlier the ph went from 7.8 to 7.49 which i heard someone say cant be right. probe error? sps are showing polyps and seem unaffected. alk is 9.5 ca is 440ppm

[quazi]

Have you calibrated it? If it calibarates correctly, I would trust it. How old is the probe? I change them every 1-2 years. Have you cleaned it regularly?

[lancer99]

Jamal, freshly-mixed saltwater typically has a low pH, even if you are using aeration, so no worries there. It will up in your tank.

 

And you can ignore the pH readings on R/O water...due to the paucity of ions (sounds like a good indie band name!), any tiny contaminants will give you wacky pH readings.

 

Not sure if you are running a Ca reactor...if so, 7.8 is typical. 7.49 is a bit worrisome though....

 

HTH,

-R