draxxes pH down not working

so I recently encountered a great pH problems which I underestimated, I have moved from soil to dwc, a broken pH meter left my soil at 13, yes 13. anyways my PHN is deep water culture system seems to keep rising drastically, it went from 5.9 to 7.2 while I was at work, could this be because of a high pH content in the plants, or does this draxxes pH down not work???

any feedback is appreciated, thank you!

PH will swing throughout the day. I add nutes, wait 30 mins, test, adjust pH and leave it for 24-48 hrs before testing again. It will always swing, which is good because different nutrients are absorbed at different pH levels.

PH up and down have a shelf life of a year I think, so if its fresh you're fine.

OK, I thought 1.2 in 8 hours was bad, just did it again, its back at 7.2, from 6.4 within the hour!!!???

can anybody say that's normal for they had any experience with it?

Also, I switched from fox farm to general hydroponics, its pH balanced, this have any impact?

Yes its normal. A swing of 2-3 would be abnormal.

Thanks