Suspected, now fact

I have had problems in the rainy season with all of a sudden the garden looking like hell. I use RO water because of high Iron content, but even with the RO, I got times that were just terrible. I was starting to notice this always occurred during the rainy cold season.

Well, we have had 21 days straight with measurable precipitation (Wierd season). For the last 6 months I have been monitoring my PH as the RO leaves me without Cal and Mag, which I add. The Cal/Mag always lowers the PH, so I have been having to watch the PH.

So on the average the PH is 6.0 before messing with additives. Yesterday, the PH dropped to below 5. Why? My theory is that the profound rains we have had lately, have literally filtered through the decaying acidic leaves, pine needles, etc and have lowered the PH. This was an overnight change, not subtle at all.

Lesson learned? Check PH whether you need to or not. Use caution around wet times and expect low PH so watch for it.

I hope this helps someone, too many winters of near death of garden because of this...

The acidic run-off is quite plausible, but are you sure your ph is accurate?
Perhaps a little extra limestone in the mix would help you through the rainy season...?

Ive noticed my tap water PH drop on rainy/cool days as compared to hot days.

On a cool day the tap will give me around 8.1 or 8.2. Then on hot days (95% of the time) my ph comes out at a brutal 8.8 - 9.0. Crazy PH...

No idea why but I have some guesses.