Parts of site failed to load... If you are using an ad blocker addon, you should to disable it (it blocks more than ads and causes parts of the site to not work).
Ph of water is about 7,5. Lowered it to ~ 6,6 - 6,7 (lemon acid) and flushed the plant with approx. 2 litres of water.
I was really impressed, that flushed liquid had ph about 7,5! That means that real soil ph level is up to 8!!!!
Damn...
Can I lower soil ph with permanent watering (provided I lower water ph to about 5,5?)
If these are accurate numbers, then you found your problem. 8.0 is when Nitrogen, Phosphorus, and Potassium will start to be be locked out from the plant. meaning it wont absorb these nutrients, which are essential. what do you mean by permanent watering? you should never keep your soil completely moist. the only exception to this rule is when they are just starting to sprout. I know polishpollack said that flushing will not help, but it may. but dont flush with acidic water. flush with properly ph'd water (right around 6.5) and continue to water with this, flushing whenever the soil's ph starts to rise.