The first thing I would focus on is your ph. You want to keep your ph between 5.5-5.8 for hydroponics. Allowing the ph to swing as far as you have can create unwanted stress and lock-out some nutrients.
Start by maintaining your ph for about a week and see if things improve. The already effected leaves won't get better, so just watch the new growth.

One other thing, sometimes a fast rising ph is a sign of algae or slime growth in the reservoir. So also keep an eye on your res for signs of this.

Hope this helps and happy growing. :hippy: