Wait so if i do gen 3 in perlite with rick wool, i should ph it at 5.5 or 5.8?
Start with 5.5 and go from there. Rock wool likes 5.5 but it will do well up to 5.8.
How are you watering using the 100% perlite? If your top feeding, that could be a little challenging, especially by hand. Looks like your in flood tables. Flood and drain would be the way to go using 100% perlite.
Me personally, if I were trying to get these plants back to full potential I'd switch to coco or even pro mix. The reason being is they will only need watering every few days until they take off. Secondly, the coco or pro mix will provide capillary action to the rock wool cube. What that will do is basically pull the excess water out of the rock wool. This brings the water to air ratio into a more hospitable range for roots to recover. Plus it will keep things simple. Once you're on track you could reconsider the 100% perlite base. It's a real high performance set up that will give great results when everything else is correct. Unfortunately it doesn't allow for any grower error. And the learning curve can be a little disheartening.
I personally use coco. As a matter of fact I've been reusing the same coco for at least 5 years without a single issue. I transplant using rock wool cubes straight into coco. I pH my formula to 5.8 and let it drift up to about 6.2 before bringing it back down to 5.8.
I don't personally use Gen Hydro 3 part but it's a good solid base. Consider running what is referred to as the "Lucas" formula. Do a search on the web, you'll find plenty of resources. It's a very easy formula. All you'll need is the bloom and micro. Add 8ml of micro and 16 ml bloom per gallon. You can supplement with cal mag if necessary. I'd start out at 2 to 3 ml cal mag per gallon. Honestly, there are lots of various formulations that will work. This one is real simple and should get you some positive results without a lot of investment.
Also, you'll have to be patient. When roots get over saturated with water they take a little while to come back. They will come back though.
Once your plants recover you can consider looking into some other nutrient formulas if you're interested. I know a couple of growers that have been using Lucas formula for more than a decade. They love the simplicity and the results.
I hope this helps you get to that happy place.
Good luck.