main cola leaf tips turning yellow?

could anyone give me any advice ive noticed on 2 of my plants that the tips of the leaves are turning yellow on the main cola the plants have been flowering for 5 days now they are greenhouse green o matics...could it be a nute deficiency? im growing them in B'CUZZ ata organics kilo mix is is supposed to have enough nutes for 6 weeks growth and so apart from a misting of weak bat guano i havent added any other nutes

1.) stop misting now unless you want moldy bud.
2.) leaf tips are hard to determine until it progresses more.
3.) nute burn, Mag def, and Nitro def are the 3 best for flowering plants but will not know until it progresses.
if leaves start to turn light green nitro def. yellow and brown Mag def, leaf tips start to curl down and brown a lot nute burn(most likely).
did you just start flower nutes?

no havent started flower nutes yet i will be starting on the next feed i will be putting bat guano on the soil and watering through.......im hoping this will be satisfactory as ive heard good stuff about the guano