Are the roots dying? I guess there are NO roots since you just started 2 days ago?
Maybe it is something on your new resivoir.. some chemical?

Have you tries another PH test.. the simple dropper method.. justto confirm your situation?
Garden Knowm Reviewed by Garden Knowm on . Reservoir problem.....Zandor? I'm onto my next grow. I am using Flora Nova nutrient feeding chart in the clone phase (light nutes). I also use half strength Cal-mag, and half strength Silica Blast. I use RO water too. I have not yet added the recomended amount of Floraliscious because I'm waiting on a delivery of new Floraliscous Plus. I have a constant PH monitor. I start out around 5.5 and it naturally drifts upward over a day or two to 6.0 before I knock it back down to 5.5 or so. This has always been my routine. Rating: 5