Jonkomaster

@Growingkitten, I'm am very inexperienced with growing and especially RDWC (first timer!) so I'm not sure what I can say about GHE. I sure don't have any complaints ! Everything is going really well and I'm totally in love with RDWC cause: - no bags of soil - no bugs (also cause I grow from seed ofcourse) - EC/PH easily measured

@Jonkomaster,Yes, PH from 6 to 6.5 in one day is ok. I used to have wild PH swings, from 5.5 to 6.8 in 6 hours. If your water temps are over 16C, you must use Hydroguard or other beneficial bacteria to avoid getting pythium or root rot. I had huge problems with pythium because of the high water temps. The dust from the clay pebbles is fine, it won't affect your plants.