Yeah that's why I thought the pebbles were making my PH swing, I read around on the net with a Google search and I found a few people were suffering the same problem I'm having. I've read some people soak them in low ph water to prepare them before hand, others say it's not necessary. I did find when I soaked the clay pebbles in water when I was cleaning and rinsing them off that if I left them in water it would make my PH rise. I did a little test to see. It's just weird some people have had the same problem, others have not. I'm using canna clay pebbles.
If I flood the table at 5.4/5.5 it will come back at 5.9/6.0. I didn't ever want to leave it more than one feeding as the PH was already out of range after just one flood etc. I didn't how ever have that problem when I was using normal water, I found it would stay in range for a lot longer.
I thought it mite be cause my R/O water has a lot less of a buffer to help it stay in line. I also held my PH pen under the over flow pipe back into the res and it would slowly raise the PH of the water coming back down.
I'm wondering if that's why some people say they add 20% normal water to their R/O water, some even say half and half. It is very strange, it mite be slightly different with the ionic tho as it says it's very PH stable. The greenhaze and Aquaflakes said nothing about being PH stable.
I'm Defintley going to have a look into the coco, I think maybe I jumped straight into the deep end with hydro, I always like a challenge tho, haha. We will see how I get on, it's not waisted equipment as I can always use it again. As you say it wouldn't cost a lot to get some smart pots and bags of cocos. Yeah your alien system looks so lush. Drippers sound easy also.
Yeah I know you're committed to the amnesia haze now, can't be throwing away good plants lol, will be good to see the blue kripple in there after tho!