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.)