SOIL pH and Living Soil/Coco Loco

[magicman]

I am getting ready for a grow, 3 seedlings sprouted Train Wreck, Northern Lights and White Widow. I will be growing in a tent in 5 gal fabric pots. Medium is Natures Living Soil and Coco Loco. I read where Nebula said to use an organic (Natures Juice ph Down) and not the liquid orange bottle stuff since it can affect the mychroids (the living stuff). (no wonder my Maui auto flowers did not do well!) Anyway question is, Natures Juice is expensive and can't I use organic, non-GMO, citric acid crystals instead? I have never had to pH up my water here only down (unless I messed up). I have read where I can and as long as it is natural, organic I don't see the difference between $10 and $49 as far as form and function of what I am trying to achieve. Thanks.