Troubleshooting form is in my sig.

I agree with martyprojeckt, looks like cal/mag deficiency as a best guess at this point. Some yellowing of fans is normal as the plant grows, too-especially during final flush when you're getting the plant to burn up stored food.

I'd lose the peroxide unless you're in hydro, and then only if you need it. In soil it won't do anything for you except kill your beneficial organisms and lower your pH a bit. (pH lockouts can prevent uptake of cal/mag even if it's in the soil; I've seen that look like your pics, too.)
DreadedHermie Reviewed by DreadedHermie on . Please!!! Need help with first grow!!! Plants are starting to turn yellow and die!!! Could somene please help me with these plants? They are 4-5 weeks into veg stage and starting to turn yellow around the tips and even beginning to die in spots. I am using 20% perlite mixed with promix and using iguana juice grow and piranha. I am currently mixing 1.2tsp per gallon of h2o. They were beginning to yellow on the sunleaves and now they are worse and beginning to dry/die. It is mostly on these leaves but it now looks as if others are beginning to dry. Pics are provided below. Rating: 5