You nailed it there, I am losing track! But I was also phing the water first, then adding nutes, I have swapped out resovoirs with water that I added the nutes to first then ph'd, the ppm were slightly less than when I did it the other way, now just to wait and see how long it holds at my desired ph. I tested some water and it was stable so it must be something that I am doing to it, hopefully switching the way I ph it helps, thanks again, you did nail exactly what I was asking!