I am superNUBE, so please forgive my ignorance, but please explain how the lime perfectly adjusts the ph of the water and the soil. And how do you measure the ph of the soil?Throw some finely granulated dolomite lime into your soil, then your ph will be dead on throughout your grow no matter what ph your water is..
Simple as that
the thing is that on the next page it says you should usually use between 6.0 and 6.5 but since the ph of the soil was so low to start out with, they used 7.4ph water for the first few waterings.The lime is a good idea, i use it myself. But, whether you use the lime or not, you still need to adjust everything to about 6.5 before pouring it in. Since your PH is a little high, it wouldn't hurt to water/feed with stuff PHed to around 6.0-6.2, but i wouldn't go any lower than that.
7.5 to 5.2 is a big jump in PH, and would likely shock the plant, so i'd recommend against it.