What's up with these??

[speedemon]

Hi all, I have noticed that between the veins on the leaves there are brown patches appearing and eventually the eges of the leaves turn brown, then the curl downwards going really narrow before all going brown and dropping off? The only thing I did different this time asw postion oscilating fans blowing accross the tops of the plants. Does this sound like severe wind burn?? or a nutrent def? Any help appreciated,pics are here.
P.s E.C 1.8, ph 5.8, week 1 flowering, temps tops 34 celcius lowest 22 celcius.

 

[speedemon]

End result

 

[Mr. Greengenes]

I'm not great with deficiencies, but that sort of looks like it needs Magnesium. Better wait for more expert opinions. On the fan, I stopped blowing fans directly on my plants over 25 years ago for many reasons, needless forced transpiration being tops on the list. I'm not saying it is your problem, actually I bet it's not, just that you might want to reconsider it's use. A small fan circulating down around the containers/rez is plenty.

 

[DocLeaf]

Yeah that ^^^ micro deficiency (magnesium, iron,calcium) , and/or more likely slightly off pH. In an inert medium the pH needs to be bang-on so the plant can get the micro-nutrients it needs,, while taking the major NPK readily... and your plants are NOT over-fed,, so we can rule nute-lock out.

We are experiencing similar pH problems just now ,,on some indica,, in an over acidic soil mix,, leaves are taking an absolute hammering

,, we'd first look at pH , thn micronutrients ,,and then salinity
(when was the last time you flushed/cleaned/scrubbed the res. out?)

Hope this helps

 

[speedemon]

Yeah that ^^^ micro deficiency (magnesium, iron,calcium) , and/or more likely slightly off pH. In an inert medium the pH needs to be bang-on so the plant can get the micro-nutrients it needs,, while taking the major NPK readily... and your plants are NOT over-fed,, so we can rule nute-lock out.

We are experiencing similar pH problems just now ,,on some indica,, in an over acidic soil mix,, leaves are taking an absolute hammering

,, we'd first look at pH , thn micronutrients ,,and then salinity
(when was the last time you flushed/cleaned/scrubbed the res. out?)

Hope this helps

The last time I cleaned the res out was 6 days ago and gave it a good scrub etc. I read that 5.8 was a great ph for absorbing all nutes??
Thanks for helping

 

[DocLeaf]

Btw,, i'm a soil grower not a hydro/coco/pebble grower,, just rust spots like that a characteristic of micro-nute def. In hydro-mediums problems are often linked more responsively,, so pH plays on nutrients, nutrients play on pH, ect,.

Also check the underside of the leaves for thrips, (tiny yellow,green,brown,black bugs) these sometimes seem to crop up when the leaf thing does,, for some reason,, IME... but we still think it's a pH issue.

Peace n flowers

 

[speedemon]

I am using cellmax which is 1cm rockwool cubes, also yeah I do have a damn thrips problem again no matter what I use even Pyrethium 5 ec I cannot keep the blighters away and from previous experience with thrips they really only damage the lower leaves but I have still pulled decent buddage. I will try inceasing ph to 6.2 and upping the nutrients to 2.0 ec, this way I have allowed for a deficiency and also a ph inrease will keep you posted, I really do appreciate your advice DocLeaf you have a great day. Also Mr Greengenes Thanks