Yellowing Problem- Please Help

[Leafy2]

Hi,
Hope you can help with a problem I'm experiencing with my latest crop- incidentally this also occured with my previous grow, before then things were fine. Whats happening is that almost as soon as the plants are put into flower the buds and surrounding leaves start to yellow really badly. the leaves take on a dry waxy feel to them and it seems to affect every bud on the plant which tends to suggest it not due to my lights being too close. Anyway the tech details are as follows. The plants are grown from seed, "The Church" by Green House Seeds (On the last grow it was "Train Wreck" by the same company. They are germinated in Root Riot blocks and fed Formulex solution until the roots develop, then they're grown in Canna Terra Pro Mix. They were fed on Hesi Soil Mix fertilizer with a small amount of Hesi SuperVit. The soil was pre-treated with Canna Rhizotonic before potting.

After 5 weeks of 18/6 under a 200W blue CFL they were transplanted into bigger pots, lights changed to 2 X 125W red CFLs and feeding was changed to Bio-Bizz Bloom until this week when I changed to Guerilla Grow bloom feed. The SuperVit was continued. Tap water was used, but beforehand it was put through a Brita filter to remove chlorine and then left to stand for 24 hours to minimize any temperature shock before the nutes were added, then it was pH adjusted to 6. The plants are watered every 2-3 days and fluid is added until runoff is observed. Temperature varies between about 18C at night to about 25C during the day. They are in a cabinet with a fan constantly blowing- extraction is via a carbon filter. humidity varies between 65 and 45%.
I've compiled the above with reference to the forums' "Problem Form" but if you need any further info please let me know. Finally, in an attempt to clarify matters I've enclosed a few photos. They should help to illustrate my problem, and the fact that all buds eem to be affected not just those closest to the light. Incidentally advice from a local growshop was that they were displaying symptoms of nitrogen depletion- is that feasible given that they are now in flower?
Thanks in advance for any help or guidance you can offer- it will be gratefully received as this problem has got me flummoxed. Cheers.

[Greenthing]

There is a link at the bottom of my post to Stinkyatticks trouble shooting guide, fill in the form then you will get the help you need.:thumbsup:

[Leafy2]

As I mentioned in my thread, it was that form that I used as a checklist to ensure i'd included all the relevant info. Do you think I should redo it as a point by point list as well? There seems little point in including the whole list in its entirity as a lot of its categories are irrelevant to my situation but if it clarifies matters,,,,

[Greenthing]

Hi Leafy, The form is there for a reason, if you want the best advice available do it.

[PlainJane]

Blimey, Greenthing, he did provide all the same info, just not in bullet point format.

But, to make things easier I would fill it out like that, Leafy2.

It does seem like a light bleaching thing. They start to stretch rapidly in those first couple weeks of flower and sometimes we can forget to adjust our lights up accordingly. The waxy feel being on all of the plant may be related to something entirely different. I wouldn't think that excludes light bleaching as a possibility. With the damage starting at the tips and the burns on some of them I wonder if they are being slightly over-nuted too.

You are using good stuff, I have BioBizz and CannaTerra pro soil as well. :thumbsup:

I wouldn't bother with the brita filter. Tap is usually fine and can actually provide some necessary minerals. Actually, that makes me wonder if you could be missing some magnesium. A few of those leaves look like they could be showing first signs of Mg def. Have you given them any epsom salts? (Magnesium sulfate) If not a couple weeks into flower is a good time to do so. One heaped tablespoon per 10 litres of water, or 1 teaspoon per 5 litres, if you prefer. You don't want to over-do it with that or you can lockout other nutrients, but if you've never given it to them it should be fine and may help.

This is only my newbie take on the matter but it's a start.

[Greenthing]

Blimey, Greenthing, he did provide all the same info, just not in bullet point format.

Only trying to help.:cool:
If you think the form is not the thing to do dont do it, but I think its the best way to get Stinkyattics attention, IMHO that means the best help anyone could ask for.
:)