I just checked the water and it was running very high on the ppms, so I flushed out 3/4 of it and just ran clear RO water in there. pH is at 5.8-5.9 and ppms are down to around 700ppm. Luckily I caught it before the plants showed any signs.
I'll let it sit in that light solution for a week and then put all brand new water/mix in there.
Dropped a little fox farm big bloom [guano] in there too. Barely raises the ppms, but still adds some soft nutes.