The salts are already built up in the leaves and plain water may reverse the flow and kill your plants so I’d just remove half the nutes and top up with RO water to reduce the ppm. Might still want to have some epsom salts for the sulfur and Mg but no extra N or P. Bit of K helps the buds plump up but there’s likely plenty enough stored in the leaves so I wouldn’t worry about that.
I get it really easy here because our RH is really low most of the year and the plants pull up too much nutes with all the extra water they drink. That gets stored in the leaves until it becomes toxic and then the leaves start to fry from the inside. Unlike regular nute burn it happens all over the leaf surface and not along the margins and tips.
Plain water will not reduce the amount of salts already in the leaves. You can try but what can happen is the plant starts reversing it’s water flow due to the reduced osmosis pressure and looks like it’s dying of thirst.
Just like this one here. I had let it reveg sitting in the old nutes for a couple months then drained and flushed it overnight with RO water. Next day looked like that so added nutes to about 500ppm and sprayed the leaves 3X/day with water. She finally came around but about a third of it died. Got a great yield from the rest of it tho.
I think you’re best to reduce ppm like I mentioned and just see it through.