yellowing leaves/stunted growth

[volak]

Please help. The pics are my 6wk old superskunk.

deep water culture bubblers. 600w hps. general hydroponics flora series nutes.

Cloning was fine. formulex and rhizotonic in rockwool cubes under fluro.

About a wk after transplanting to the bubblers, yellowing of the larger fan leaves started.

guy in hydro shop suspected heat stress, so i substituted my open reflector for a cool shade.

Still the yellowing continued. Suspecting the nute solution, I changed it for fresh. Used the recomended dilution ratio, and ph'd the solution to 6.

Also added a little superthrive to the mix.

I like to crop all the side shoots when i flower so as to finish with 1 large bud. This has worked fine for me previous, with coco medium and nutes..but this time, i noticed the new shoots were comming out twisted and deformed, and the budsites are much smaller and spindly than i would expect.

They are now 2 wks into flower on a 12/12. And as you can see, they look half dead.

My temps are fine, good air circulation, only thing i dont know about is nute solution temp.

Too add..my mate has EXACTLY the same setup, same clones from same mother, same nutes same everything, and he has grown some monster buds.
As did I last crop.

The thing i cannot understand is that i have changed nothing. I have used this system for 12 months..all fine..now i am spontaneously getting probs.

Im stumped.

wat do u all think ?

volak Reviewed by volak on 04-05-2009. yellowing leaves/stunted growth Please help. The pics are my 6wk old superskunk. deep water culture bubblers. 600w hps. general hydroponics flora series nutes. Cloning was fine. formulex and rhizotonic in rockwool cubes under fluro. About a wk after transplanting to the bubblers, yellowing of the larger fan leaves started. guy in hydro shop suspected heat stress, so i substituted my open reflector for a cool shade. Rating: 5

[phatsesh101]

i think you should fill out the form.
it helps to narrow questions to many at this point starting with water

[volak]

E-indoor or outdoor....indoor.
E-soil, soilless, coco, aero, or hydroponic....hydro.
E-specific medium.... clay pebbles
CSL-Soil type/brand....hydroton
HCL-Hydro/aero/soilless system type....deep water culture.
SCL-Anything you have added to the soil
SCLR-Soil or slab runoff pH
E-Water source....tapwater
E-Source water pH....7.0.
HRT-Source water EC (if hydro)
E-Age of plant....6wks
E-Type of fertilizer....flora series
E-Rate of application (if hydro, this is your PPM number, preferably after each component is added)
E-Lighting source and distance from plant....600w hps coolshade, 2.5 feet.
E-Air temperature (both day and night if you are running a dark period)
HD-Reservoir temperature
E-Air % Relative humidity
E-Lighting schedule....12/12
E-Type of ventilation your room has....fan in/fan out/oscilating fan inside.
TR-Did you pre-soak your media in pH corrected solution?....no.

There ya go...hope i did it right, couldnt answer all the questions tho.

[Divestoned]

your PH needs to be at 5.8. But it look's like the classic "over-watered". Lets start by changing the ph and go from there.


Dive:stoned:

[volak]

A close up of one of the leaves. Looks like some kind of nute lockout to me..but what and why..baffles me.

[denialisback]

your PH is too high for a hydro setup.. you need to reduce your PH nutrient solution with some PH down.. 6.8 ought to do fine, but im told on firm assurance 6.2 is really where its at for hydro.

Hope this helps.. cause this explains a possible simple solution to your problem.

Remember, add a bit.. if it starts to recover.. add a bit more the next day or too.. not too much at once!! NOT TOO MUCH AT ONCE! :-)

I say that twice, because you don't want to seal your plants demise.. hehe

Have fun.

Peace,
Denial

[denialisback]

A close up of one of the leaves. Looks like some kind of nute lockout to me..but what and why..baffles me.

I would imagine so PH 7.0 is a bit high for hydro, you'll probably get lockout..

heh that leaf literally looks stereotypical of the suffering of reverse osmosis..

one more thing ... For flower use phosphorous acid ph down in your res.
For veg use nitric acid ph down in your res!


ALSO: If nothing has changed and you are using the same phenotype plants, its guaranteed to be a change in the water type or the amount of watering your giving/these pheno's need... worth looking into also.. well pointed out divestoned.

Peace,
Denial

[volak]

ok, my ph is now just about 6. Overwatering ? The roots are completely submerged in the nute solution...which has an airstone in it.
I grow in deep water culture bubblers.

[volak]

There was some confusion with the form. I thought the 'source ph' meant the ph of the water when it comes out the tap...which is about 7. I always ph down to about 6, but with phosphoric not nitric.

[denialisback]

There was some confusion with the form. I thought the 'source ph' meant the ph of the water when it comes out the tap...which is about 7. I always ph down to about 6, but with phosphoric not nitric.

ok well phosphoric acid is the right thing to use in flower anyways :thumbsup:

If your PH is 6 you shouldn't really be getting lockout.. is there any possibility you are overnuting them? this can also cause the same symptoms, mainly lockout.. too much phosphorous maybe?? This could be the case if you are using a high phosphorous content fert and lots of ph down? Let us know :thumbsup:

Oh, also, what is your PH runoff?

Peace,
Denial