Grow update, with leaf problem

hi peeps:)
im well into the flower zone now, got some chunky looking buds forming, and resin glands starting to appear on about 20% of the little bud leafs.

after the hermie scare i over reacted and topped one of the plants, but its top bud i chopped had previous light burn and was growing in a very suspicious way.
the two secondary buds laying underneath were more than happy to take on the job....a bit stuntted,its fallen behind the otherplants in terma of development but i guess thats only to be expected.
......no more signs of hermie ...........yet

one plant is causing a bit of a concern, most of its primary sun leaves have this creeping brown/yellow problem that starts at the tips of the lower leaves and is gradually working its way inwards and upwards.

other plants are also having this problem but its not half as advanced as it it in this one.

during this grow, ive learned a very valuable lesson, which is...

its better to take no action untill you know for sure exactly what the problem is, rather than jumping to conclusions and making the problem worse.

my theroy is...

im using pre-fertilised miracle grow soil, and now realise, *i think* the problem being the time-released nute in this soil, is that you get random, unpredictable "spurts" or even overdoses of certain nutes.

i was kinda wary of this potential problem when i set out, so ive held out using extra fert.

ive given the plant 3 doses of 10-9-19 at half stregnth in total, one right when i switched the lighs over, one when i saw a good ammount of white haier, and one a few days back, so spaced over about 3/4 weeks.i think that coupled with the random pockets of nute in the soil may be the problem, or at least a contributory factor.

tdjgf

I dont mean to steal the thread or anything but just curious, how long are those into the flowering phase?

Yeah, those crispy tips are burnt.
Be wary of giving N during flower. You are supposed to withhold it to get more budding. The way I give N is when I repot into the pot they will flower in, I mix some fish glop into the soil for the roots to find gradually.
The yellowing lower leaves are normal that late in flower. No worries. But you are going to want to flush out that pre-ferted dirt with copious water.

Mirical grow sucks.
Don't use it.
It's sheap to buy good soil.
And your plants will repay you.
How many times does this need to be said.
MG sucks for MJ!!!

its been about a month of flowering, but i havent been counting the days.

i think it should be said, that one plant ( the one thats burning ) is in a different kind of miracle grow to the rest.

in my local garden center has like 3-4 different types of MG soil.

the one type thats worked out ok is "moisture control compost for pots and baskets" there is a bit of burn with this soil, but im not concerned about it, as its pretty minor at the moment.

a couple more pics of the worst affected plant, out of the grow room, in better light.

its lookin ok for now but with a lack of big healthy lefs im a bit worried for its future.

my camera and HPS bulbs dont agree with each other lol

how long have they been flowering??

you have calcium deficiency

and you have magnesium deficiency

add 1 tsp of epsom salt per gallon of water you use

also add 1 tsp of hydrated lime per gallon of water you use

make sure u use distilled water

and make sure the shit is disolved, hydrated lime is hard to find order it from somwhere

both of these problems slow down the growth of the buds, and make the leaves turn brown on the ends and curl up slowly

nute deficiency cant be the problem, its a comprehensive nute.

im using 2-part "vita-link bloom" 10-9-19

the full spec of fert is listed as: nutrients are:

nirtric nitrogen 0.375%
ammonic nitrogen 0.375%
nitrate nitrogen 4.25%
potassium 9.6%
phosphourus 4.59%
calcium 1.75%
magnisium 1.46%
boron 0.0087%
copper 0.002%
iron 0.068%
manganise 0.0145%
molybdenum 0.0013%............dont know what the fuck that is, lol
zinc 0.0098%
cobalt 0.0013%
nickel 0.0013%