EC of what you were feeding them was 4.5? Or runoff?
The runoff was - however I had not been watering much to runoff so I think it was full of salt (hence the fucked up looking leaves?)
Like I said, focus on the strength of the feed you are giving the plant. That is what matters. Salt build up from lack of runoff is definitely a possibility for the issues.
I didn't have an EC meter before - nor did I even know what it was (I do now). I'm hoping the next grow is better - dropping the FF trio and using Mega Crop.
Try it at 1 ec, and water to plenty of runoff, you'll get the hang of it.
You going to be using the one part MC or two part?
This is what I ordered - MEGA CROP – Greenleaf Nutrients
That’s the one part. It’ll do a great job start to finish but be careful with feeding amounts. Definitely make use of your EC meter after you mix up the nutrients to know what you are giving the plants.