Dean8

If your pH is at 4.5 your poisoning your plants. Hydro is 5.5 - 6.5, I like 6.0, soils are 6.0 - 7.0, I like 6.3 in my soil. It sounds like something is getting mixed wrong. What order are you adding your nutrients? pH perfect should go to 5.5, also what's the pH of your water before adding?

I would start by mixing a lower feeding together. And test the pH, you could be over mixing. If you mix a smaller dose together and it comes out the same way then there is definitely something wrong with the nutrients them selves. You could always go buy bottled drinking water and test the pH perfect nutrients out on that. Also are you sure your pH meter is in adjustment?