Can Anyone Tell Me What Causing This...

Newbie here.. What can be causing the leaf to turn yellow at the tips and curl up as shown in the pic below?

Medium: Miracle Grow Time Release Fertilizer
Water: Distilled
Nutrients: Master A and Master B by Humboldt Nutrients

Nute burn ? You're using MG time release fert and humbolt A and B seems to me that's a bit much.