Having problem with my plants

Hi,

I´m having a big problem with my plants, the leaves always start to get rusty and ugly on the week 5 - 6 in flowering. I use Atami nutrience

so in 100l tank i use

hitro A 100ml - 130 ml
Hitro B 100ml - 130 ml
atazyme 200 ml
ata xl 100 ml (start on week 3)
bloomstimulator 100 ml (start on week 3)
pk 13 - 14 (start on week 4 - 5)

some plants get rusty and 3 - 4 plant are dying or something

Please help me

Thanks

what is your PPM and ph? it looks like you are burning them to me. maybe change the res and cut back on the fert a bit and see if it helps.

and how much Cal mag are they getting?

How hot is that room? They look VERY hot, like way cooked hot.

Heat/light stress. Agree with Doc redo your rez.

more pics with the hps off would help too.

here are some more photos,

i forgot to tell you that i use a burner to make the co2

there are 3x 1000w hps and 3x 600w hps in the room.

the EC never goes over 2.0

i use half of this system
http://growanleitung.growland.net/wp-content/uploads/2009/05/willam-system.jpg
just the tray that is underneath and a white phc plate over and there are seven holes in for 7 plants and for the air is 2x 150mm meteorite so the roots get oxygen.
there are 9 of those in this room.
And then i have 25.000w air cooler but the tempeture is about 30° right under the lamp but there are fans which blows on them.

Bump

The whole plant pics tell me that it was a heat issue some time back.
New budding growth seems fine and heat appears to be under control.
Next time keep 2ft between lights and canopy (60cm).
Brief periods of high "felt" heat at canopy level will give you that "burnt" look.

So you would think it's burned because of the light? not nutrience burn,

but what about the heat in the room ? do they get like this because it's to hot ?

IMG_0006 do you also know why she does this ?

please comment on my setup if you could tell my what change could be a good improovement

IMG 0006 = The roots got over 70F and caused death.....RES temps should NEVER get over 69F......some strains are more sensitive to this problem then others......Berry Bomb is a good example,,,roots are very temp sensitive!

Ambient or "room" temps can be misleading.....The canopy level temp is effected by the proximity (distance from the light to the canopy) a lot more then people think. Your room temp could never go over 75F and you can still get the heat stress from the closeness of the light.
Put your hand at the canopy level. How does it feel after being there for 1 min? Hot? Move light up!
Now then. Ambient room temps are best kept between 65 to 80F.....When the room temps creep up over 80. The plant begins to use it's energy to keep cool. At 85F it actually begins to slow WAY down and at 90F it is just about "dormant" as far as any growth goes. It's using all its energy to stay alive by cooling it's self with very increased transpiration levels. This leads to it using vast amounts of water/feed solution. This brings on other problems...

No, that's not a nutrient "burn".
I would add a Ca/Mg product to your mix.....and a Silica also. Silica helps the plants temp tolerance and helps regulate P uptake.
Use of C02 in veg is not worth the cost vs. the benefit.
Stop C02 at week 6 so the plant can finish properly in a timely manor. (longer in a relative way for longer running plants).