Help! Can't work this one out. Bleached leaves and pure white flower tops.

I have hit a problem. Half-way through a scrog flowering period a few tops have started to go funny, mainly directly under the light. The leaves are showing inter-veinal yellowing, like mg or Fe deficiency. I have just added some epsom salts.
More worrying, on the same tops that have yellow leaves, the new flower growth is pure white, just at the tip. I am unsure whether it's a mag def or light bleaching. This is my first grow in this cupboard, although I have used the same hydro system and nutrients before without problems.
Temps seem OK. Peaks at 85F and dipped to 60F over last 24 hs.

Anyone any ideas?View attachment 2259346On the plus side, I just fast-dried and smoked this bud I picked for the Photo and I am w*nkered!

Its very def because the ph is wrong.

Cheers buds. Appreciate the quick response. I just checked it and it's about 6.5. Way higher than I normally have it (5.5 ish) Do you think that's the problem?
I am in hydroton. Just put some ph down in and will check again in the morning.

Thats weird looking, like some flower shop mutant.

O.K. So today, it looked worse but only the tops under directly the light. pH is down to 5.5.I've done something a bit weird. I've tried to do a kind of simple LST on the top ot the screen. I've 'twisted' the taller affected buds onto the shorter ones.

From what I can see it looks like light bleaching.

indoor grow i take it. Have you been razing the lights as they have been flowering?Did you put them out in the sun?

Ku$hking3883 said:

indoor grow i take it. Have you been razing the lights as they have been flowering?Did you put them out in the sun?

Click to expand...

Neither is an option.

250w hps, GHS Big bang fem (Indica). scrogged. Mini-grow. bulb was 7 1/2 " above closest tops.4 weeks into flower

light bleaching most definitely no doubt about it

and since raising the light isn't an option just tie those branches down as much as you can. it doesn't matter if they lie on there sides in fact it may help you yield more

Well, guys, just so I don't leave this unfinished, I ended up hitting it from both sides. LST above the screen wasn't an option as it was so dense. Added epsom salts and removed some Buds closest to the light. (needed some smoke). Seemed to improve. Have now harvested half (am unfamiliar with this strain so want to split the harvest) and all is going well. Dried 1st half 4 days (has been hot/arid here) and jarred up but showing 72.8% RH in my test jar so have to be careful and leave the 2nd half 5/6 days.
Considering I have probably already cut an oz off it, yield seems very good despite the problems.

Is it growing between your legs, that what it looks like