Lighting Distance from plants without lenses/reflectors

[Site]

its all new growth so its a bit different to look at and always seems to come out a bit droopy but i definitely think the plants were in the sweet spot and now they have grown like 3/4 inches it might be too close again...i did water them last night but the tips going a pale color got my a bit paranoid...its not like nut burn that ive seen before when i did my first grow...