[Thunder Fist]

Morning folks, need help asap. 23 days into veg under 400w MH in a DR90. Worst affected plant had bottom 2 leaves removed , here is one i removed



Yellowing starts at the bottom leaves from the base of the middle vein. New growth seems very yellow and quickly develops necroric patches on top of the leaves near the serrated edges. Here is the worse affected plant

More pics to follow........

[snatch]

need more info mate temp nutes wot u growin in etc

This post has been edited by waldo: 23 March 2012 - 10:21 AM

[Evilscotsman]

Are they in straight hydro rocks mate? what feed you use will also help? what ph do you run? Thanks
(Evil)

[Thunder Fist]

Sickest looking plant .

Leaves are a sickly looking yellowy green with some intervenal yellowing. Looking like all plants are becoming affected I'm thinking either fungal/environmental problem.

Temps are good. I've got passive ducting in , 4 seperate bits of ducting that are quite long so possible restricting airflow? Any help much appreciated. Cheers in advance.

ps plants seem to be lacking vigour, new growth seems a bit spindly and more stretchy I think.

[Thunder Fist]

Evilscotsman, on 23 March 2012 - 10:23 AM, said:

Are they in straight hydro rocks mate? what feed you use will also help? what ph do you run? Thanks
(Evil)

Sorry , no in PM soil with a layer of hydroton pebbles on top. Feed wise using small amounts of catalyst and biosilicon occasionally, annd they've had a spray of PM essence yesterday which didnt seem to perk them up as it usually does.

[Evilscotsman]

There may be a few things going on here mate could you please put a quick post of, medium used, nutes used, feed in ph, runoff ph, temp lights on and off...
i know its a pain, just we would all be guessing without a lil background info man, Cheers
(Evil)

[Frank Lopez]

What's the root stock like?

I'd pot-up if I were you. That PM soil is really nice stuff but doesn't contain much nutrients.

Looks like you've topped your plants so I'm guessing their about 4 weeks old now, that's about the limit for that soil IMO.

[Thunder Fist]

waldo, on 23 March 2012 - 10:21 AM, said:

need more info mate temp nutes wot u growin in etc

Temps about 18c-27c. Humidity has been pretty low ,around 30%.

They've all been recently topped and potted up within the last 5 days. I think I was a bit late in repotting some though.

Nute wise, only benificials so far like catalyst, silicon and bio-wetter. 2 sprays of essence, one yesterday and one 2 weeks ago.

This post has been edited by Thunder Fist: 23 March 2012 - 10:38 AM

[Thunder Fist]

Frank Lopez, on 23 March 2012 - 10:37 AM, said:

What's the root stock like?

I'd pot-up if I were you. That PM soil is really nice stuff but doesn't contain much nutrients.

Looks like you've topped your plants so I'm guessing their about 4 weeks old now, that's about the limit for that soil IMO.

All have been potted up within the last for days, so at least another week before they fill these pots out. Was going to flower in these pots too , keeping the plants smaller. 3 WEEKS and 2 days old today. Let them get to 5/6 nodes and topped at 2nd node. Topped between 5-7 days ago.

Thanks everyone by the way..

This post has been edited by Thunder Fist: 23 March 2012 - 10:43 AM

[Frank Lopez]

18c is the bare minimum you should go mate. anything below that will cause you lock out problems.

Have they dropped below this in the last few week? i.e. in the middle of the night?

Does your temp reader log the peak high and peak low temps? i.e does it show what was the lowest point in 24hrs or does it just give a single in-situ reading?

[Thunder Fist]

I sealed up my passive flaps a few days ago and put on 2 more bits of ducting from the top vent holes, so I have 4 pieces of passive ducting in total, 2 at bottom , 2 at top.. they are quite long long though so I'm thinking restricted airflow possibly.. i dont know thopugh

I've opened a passive flap up a bit this morning too.

[Thunder Fist]

Frank Lopez, on 23 March 2012 - 10:45 AM, said:

18c is the bare minimum you should go mate. anything below that will cause you lock out problems.

Have they dropped below this in the last few week? i.e. in the middle of the night?

Does your temp reader log the peak high and peak low temps? i.e does it show what was the lowest point in 24hrs or does it just give a single in-situ reading?

It records high and low.. lights off have been 4 hrs during the day and I have an oil filled rad in there but I did take that out a few days ago and my temp had went down to just over 17c.

Ill get it back in for lights out this afternoon though. Generally though for most of my grow lowest temp has been above 18c.

[Evilscotsman]

Stay on sick plants section, scroll down to post...Is there a docter in the house?...i think it'l help you out mate, the lil scars look a bit like Cal def but theres alot more going on...gna check be back the now mate... (Evil)

[Thunder Fist]

Evilscotsman, on 23 March 2012 - 10:51 AM, said:

Stay on sick plants section, scroll down to post...Is there a docter in the house?...i think it'l help you out mate, the lil scars look a bit like Cal def but theres alot more going on...gna check be back the now mate... (Evil)

Cheers mate.. ill do that now..

[Frank Lopez]

anomalies like this are most likely due to environmental issues, this one looking like low night temps.

17c wont have shocked it too much, dip below 16 and your plants might even stop growing or be severely stunted.

From the looks of it you've caught it just in time.

best course of action in a situation lie this is too get the basics sorted i.e. temp & ventilation. Then if you still have problems you could question weather its down to nutes or disease.

They look fairly healthy to me apart form the non-descript spots which is most likely caused by a lock out of '?? (who knows which)' element, could be anything but most likely the cause is lock out due to temps IMO, and it happens oh so often.