Yellow tips, brown/yellow spot on leaves

[homegr0wer]

So, my girsl are vegged for 4 weeks now and i just changed lights @ 12/12. At the beginning i noticed a little yellow spots on leaves, but it wasnt a big problem and growers told me that its just a light burn. Now the problem is real.

Temps under 30 celsius degree (=under 86F)
Pots are 10 litres (= 2.64 gallons)
Light is 600w and 60cm away (=23.6 inches)

Been using biobizz grow @ 1ml/1l and raised it to 2ml/1l
At the last watering used bloom and topmax 1ml/1l

Plz help me! (And english isnt my native language, sorry about that )

 

[Hans-von-Dampf]

from what I can see this might be the onset of a calcium / magnesium def
maybe some heat stress, too (twisting leaves)

are you PH-ing your nutrient solution? it might be that your soil PH is off, so the plants cannot absorb the nutes you're feeding them

fast solution: foliar feed a mild cal/mag solution. spray it under the leaves

long term: Get your PH in check! 6.5 should be ok for soil. measure the PH of the nutrient solution you feed them, correct it if necessary. if you don't get your soil in order, all the nutes in the world won't make a difference. the plants won't be able to absorb it.

PS: the leaves shouldn't be covered in dirt like that. they shouldn't touch the soil at all. this invites all sorts of troubles, mostly mold

that's what I got. Battled the same symptoms in previous grows, this was my solution and it worked

 

[homegr0wer]

are you PH-ing your nutrient solution?

Im not and i dont have a ph meter. How good ph meter do i need to get useful data?

fast solution: foliar feed a mild cal/mag solution. spray it under the leaves

Yea i did that now, i tryed to mix a tea spoon dolomite lime and 1 litre water, lets see what happens. (From florist's)

PS: the leaves shouldn't be covered in dirt like that. they shouldn't touch the soil at all. this invites all sorts of troubles, mostly mold

Yea i know, i think i started to tie them down too late and they ended up like that. I have to try rise them up someway i think.

 

[Hans-von-Dampf]

I bought a pretty cheap one ($20 or something like that, from amazon, the cheap yellow bastard)

It's alright I guess, pros would probably not go for it though

I have to recalibrate it with every other measurement (buffer solution at 7.0 and 4.0), and I think it's close enough. I get my constant 6.5 and that's all I need to know (I don't care whether my PH is 6.5 or 6.52, I grow on soil ... one decimal is good enough for me)

 

[GrumpyToker]

I agree feed her some cal-mag

 

[homegr0wer]

Did that, looks good so far. I was thinking a cheap ph meter from ebay, but calibrating on every other measurement, jesus.

http://www.jencoi.com/index.php/ph-tester/item/610
That costs 75€ on local store here, would it make a difference? Is it too expensive to my use?

Thank you guys!

 

[homegr0wer]

Bought $20 EC/PH meter from ebay and im waiting for it. There is my progression if some1 is interested. Day 26 from 12/12

 

[homegr0wer]

Wrong image, lol

 

[Farmer B]

Don't forget to order calibration solution. I had that yellow one. Works but had to calibrate every week or so. Finley the lil glass bubble broke

 

[Hans-von-Dampf]

I wouldn't worry about the calibration too much

you take your 7.0 solution, fill a little container until it's enough to sink the PH-meter in, turn the screw, shake & watch, adjust until the PH-meter shows 7.0

if you want more accuracy, you also get a 4.0 solution and to the same until both show the proper measurement result ... but I usually just do the first and only range calibrate once or twice per grow

just don't re-use the solution and don't put the PH-meter into the bottle ... it'll mess up the solution

 

[Bush Dr]

That plant is grossly under fed, in early floral the leaves should be dark green

When I grew in soil with Bio Bizz I always gave them the max dosage, 5ml/litre as I recall

If you're growing in soil adjustment for pH doesn't matter

 

[Farmer B]

That's funny ph doesn't matter lol ^^^^^^^so if I water my plants with 8.0 ph tap water then next time add my nutes witch comes to 5.5. I wouldn't have a problem. Lol
Wouldn't worry about calibration to much and then discribe how to do it. Crazy