It's hard to say now because you've used epsom salt but it appears that you have nutrient lockout of some sort.

1. Either your pot is too small and you're rootbound really badly.
2. Your soil ph may be 6.5 and water may be 5.0 but what is your soil runoff ph. That's what we really need to know. The reason why I say this is because it looked like you either had a ph problem or a deficiency.
3. How much did RO did you flush with? Did you add calcium or magnesium? This is important especially after doing a flush.

I'm going with either PH or rootbound on this one, but it's hard to say on this one because you may also be suffering lockout due to the epsom salt.
daihashi Reviewed by daihashi on . Problem with new growth I have a problem with the new growth on my plants. The tips of the new growth are turning yellow almost white. They are in the fourth week. Planted in MG Organic Choice (I know I know). 400 W about 15 inches up from tops. I have used 1tsp. of Epson salts/1 gallon water twice. No change in the last few days. Seems that they have slowed in growing as well. I haven't fed them any nutes as of yet. I do use well water, could that be harming them? The PPM could be high. I have searched but seem Rating: 5