New Grower PH changing overnight

[SMOOTHseven]

Hey guys I built an aerated gravity feed drip system yesterday. Loaded it with nutes and PH'd to 5.7.
This afternoon I went to feed them and I checked the ppm and PH before I turned the valve. The PH had rose to 6.5 in just 12 hours. what gives?? any clues to how it could change overnight?

The rest of my grow in SIG

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[SMOOTHseven]

I PH'd it before I feed at noon. its 8 hours later and I just checked it and it at 6.3? why the hell is it changing?

 

[Gatorbackbob]

It's called the swing I think, maybe try to mix the night before, then RE adjust ph after 24 hours just before filling res?

 

[SMOOTHseven]

I re PH"D and it went back up again

 

[MeefChief]

What nutrients are you using?


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[SMOOTHseven]

bump

 

[SMOOTHseven]

What nutrients are you using?


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My grow log in my signature documents it all.
Calmag+ 5ml/g
Canna A&B 7ml/g

 

[SMOOTHseven]

I have been watering by hand until I set my scrog, its getting a little difficult so I set up the drip system. The ph in the reservoir keep rising.

 

[Gatorbackbob]

What about pre mixing 24 hours before, as mentioned above, but ph to 4.7 and see if after a day it will be where you want it?