Grrrrr please help diagnose this pleaase!!!!!!! pic added!!!!

Hello all, can someone diagnose my friends problem please?

after 4th week of flowering 2 out of his 4 cheese plants have started to turn yellow on the fan leaves, to the point where at the end they crisp and roll up.

he uses canna coco a & b 30ml per litre, canna boost 30ml per litre. The ph is around 6 - 6.1....the canna range ph seems to be quite stable.

Its weird the way 2 have gone like this and the other 2 are really green and doing well.

I find it hard to believe that its nitrogen deficiency so late on? could be though as he is no expert.

also magnesium def?

any help would be massively greatful.

also i would like to add that the 4 plants are from the same reservoir, and the other 2 healthy plants are to the point where the tiny tips are burnt a touch (close to overfeeding) but perfect.

Yo man, cant see it being N def, why dont you try lowering your PH to 5.8? 6.1 seems a bit high for hydro!

looks like nitrogen issue, personally id try a little grow nutes in it. it could be nute-lock have you tried some epsom salts or cal mag?

just ordered some adanced nutriants sensical mg bloom, hope that will do the trick. canna recommends feed between 5.8 and 6.3 for coco so am ok for ph levels, cant see how im getting nutrient lockout thou? as ive said the other 2 are flourishing. really annoyed coz av done plenty of research and cant get to the bottom of it!!

does anyone know the best way to clear up nutrient lockout as im growing with coco in autopots? thanks

Yo man i would seriously consider lowering your PH...im in coco also and feed at 5.8 every time. Try it...
http://hydro-heaven.com/yahoo_site_admin/assets/images/ph_Chart_3.208114926_std.gif

i use epsom salts twice during flowering to stop it. seems to work for me.

At 6.0 your locking out potassium & phosphorus. Also u aint getting any calcium...at 6.1 its even worse! Drop it down and ul see results trust me

thanks i will give it a go!!! calmag is the same as epsom salts right?

ste147 said:

thanks i will give it a go!!! calmag is the same as epsom salts right?

Click to expand...

Never used epsom salts but from what ive read its more or less the same thing ye. I use cal mag at half strength now and again in flower. Every 3rd feed id say. Dont over do it if u get some

more or less mate. think the cal mags in liquid form though.