Spotting and weak leaves

[FastForward]

Something is definitely not right with my plants. Many of them have brown spotting on them, and some the leaves are looking dry and brittle. One has broken (might have been me but I doubt it) and others look parched in the middle. New growth looks fine.

This has all happened since I made the mistake of turning off the extractor fan to increase humidity...which caused algae probs and all kinds of crap. I'm worried that this is some kind of fungus that developed in that period (3-4 days ago). Since then I've got good circulation and extraction, room temp is 21, nutes at 20 and have added in peroxide but they're not picking up. I also might have had the nutes a bit high at 0.8 so does this stuff look like burn??

Any ideas? Also, I've got 9 lowryder seeds germed and heads up in cubes in the tent. If this is fungus do I need to kill all the affected plants? Or can I cut off the leaves? Or is there any kind of foliage spray I can use?? (p.s. last photo I was messing with the colour balance in camera - it's not that yellow irl...it's to show the spotting...and that one is one of the violator girls :( )

thanks lots...

 

[Zoolander]

Looks like the first stage of mag def , Mine look like that and I add around 5 ml of cal-mag and it is soon gone . Lets see what others say .:)

 

[ProGroWannabe]

I would have to vote for a mag deficiency as well.

What's up with the one in pic #3? Did it get too close to the light? That one looks a lot like it was affected by heat stress.

 

[FastForward]

I would have to vote for a mag deficiency as well.

What's up with the one in pic #3? Did it get too close to the light? That one looks a lot like it was affected by heat stress.

They're under 2 x 55w fluoros in a sunmate prop reflector. I've been keeping it 5-8cm from the tops of the plants but maybe it was too close? I figured fluoros was best to keep as close as poss. Have moved lights away and added Hygrozyme. They're getting GH Nutes so it mst be a lockout of sorts? I'll give it another day or so and then will flush with water...

 

[ProGroWannabe]

Moving them away a bit won't hurt a thing at this young stage.

Also, do you have any type of Calcium/Magnesium supplement....ie Cal/Mag, Cal/Max, or the like? See if someone else chimes in, but it would be best to give them a small dose for the Magnesium. I'm sure you haven't fed them doses high enough to lock the Mag. out, they just aren't getting the little bit that they need....IMO.

 

[British_Hempire]

Could also be a little bit of ph spotting going on.

 

[FastForward]

Could also be a little bit of ph spotting going on.

Would that be caused by too high pH or by too wild fluctuations? (my pH hasn't ever gone above 6.4 but it does swing a lot...have stopped adding rhizo to stablise it) If it is pH spotting, what do I do to fix it?

 

[Midnightgardener]

re

stabilise your ph, you can correct the problem with a good foliar feed, if you can get this one then try it,it costs a bit but is real good, b.a.c foliar spray www.baconline.nl
you are using a uninfluenced medium as far as i can see, so you have to make sure the nutrient reservoir is correct ie.ph is stable and ec,
whats nutes are you running?, im sorry if you said it already,read your post but not sure if you listed those details...
regards
MG
if u stabilise your ph and ec then the prob should go away, foliar is a fast remedy..