White Tip Fan leaves

Healthy Marley's Collie, indoor grow, also have one White Widow that was exibiting same problems, water solved Widow, not Collie...using Bat Guano less 1/4 strenght.
Watering about every other day...whats the deal.

That doesn't look like "white tips" those look more like a deficiency. Possibly cal/mag? Does your soil have extended release nutes in it? Or your lights might be a little close and your burning or bleaching the tips of the leafs.

No I avoided extended release, but I bought a bundle of Pro-Mix BX. This soil dosent have extended release nutrients but does have some sort of bio additive.
Checked the Marley this morning and it seems to be recovering.
Did a PPK test on BX, everything in excellent ranges except nitrogen which was a little low, I wanted this because of the additives Im using.
Im watering every other day, none of other plants are exibiting symptoms, dont want to increase my program, I will just pay closer attention to this particular plant.

Thanks Bam...good advice on cal/mag possibilities I will look into it. (If all else fails read the contents of the package)

Figured it out...forgot added 3:1 worm castings @ 1-0-0. This means the lower nitrogen levels within BX are mute. Have to do another test.