whats happening?

[ShOrTbUs]

i don't see the ph drift being a problem for you though. it's a bigger concern for people who use reservoirs. for you though. since you will be mixing a new nute solution every other time you feed. you don't have an accurate way of monitoring your soiless mix for ph drift. your mix, because it is inert will naturally become whatever ph your solution is when you feed. your best bet is to start by phing to 5.5, feeding the plants, and observing how they react. then increasing the ph slightly on the next feed(5.8). and continue to observe. you will notice that different strains will respond differently to not only varying strengths of solutions, but also different ph's. you will also notice that the plants may react better to different ph's when you switch from veg to flower.

 

[MoNoXiDe]

Here is a updated pic. After a 5.4 ph watering and a couple days of soaking.

 

[ShOrTbUs]

looks like the leaf curling is starting to subside. thats a good sign. the yellowing might never go away, but as long as new growth is remaining green your good to go