Ph issue or deficiency/toxicity?

[Facelesdoll]

So I was over watering for a while and had pH issues also. But now I seem to have them back on track where all of a sudden on two or three of 8 plants is displaying some sort of an issue that seems to be worsening. The leaves are still green even where damage but just a little paler green and are crinkly paper dried and dead toward just the brim of the leaves. Where the rest of the leaves look good it is just the edges on three different strains. Nothing too severe yet but I know there is something going on. 50% happy frog soul 50% coco choir with grow stones( lot like perlite) I ph my water to 6. On 5 week old plants I am two feedings in on the seedling regiment for vegamatrix in use with og tea now(fungi and bacteria with tea to feed the cultures) This had appeared on nearly a half dozen leaves starting from bottom range to middle of plants and having looked fine until now. On the second feed I went with a little extra boost which is the calcium magnesium part. They are under a 150w Mh. at 74 degreesf.

 

[Facelesdoll]

Yes that leaf was cut like that when topping to get the lowers more light. However it has the burnt edges which appear to be issue here.

 

[fatalxerror]

New Growth looks fine to me. That usually happens on those first set leaves if it needs the nutrients. Let the plant dry out between waterings. Also if you are ph water with ph up or down you are killing beneficial bacteria in the soil. If ph of water is 6-7 dont worry about ph it. The bacteria will adjust if you are using all organic nutrients if you use synthetic they die. To keep soil ph neutral instead of adjusting the ph of water add some powdered dolomite lime 1tbs per gallon of soil, it will keep it at 7.

 

[Facelesdoll]

My tap is 8 to 8.5. Lime will do it mixed in the water?