What's up with these leaves??

[Colliedude]

What STRAIN are you growing? Ice, Northern Lights & Big Bud
What was the establishing technique? (seed or clone?) Seed
What is the age of your plants? 7 weeks
What PHASE (seedling, vegetative or flower) are the plants in? Flower
What size pots are you using? 10 liters/2,6 gallons
What substrate/medium are you using? 70 % Sphagnum peat moss 15% Perlite 15 % Vermiculite
What Nutrient's are you using? Canna Terra & Bio Bizz Top Max
What is the pH of the "RUN-OFF"? 6,2-6,8
What method of pH test was administered? Adwa Digital ph meter
When was your last water? Today
When was your last feeding? 4-6 days ago
What size bulb are you using? 400 Watts/6 plants
What is the distance to the canopy? 30 centimeters
What is your RH Factor? (Relative Humidity) 30-35 %
What is the canopy temperature? 27-26 celsius
Is the fan blowing directly at plants? Yes
Is the grow substrate constantly wet or moist? No
Has plant been recently pruned, cloned or pinched? Yes
Are plant's infected with pest's? No

As you can see in the last pictures the plants look pretty healthy except the lower leaves. First I thought that I had burned them by spilling the nutrient solution on the leaves, but even some of the higher leaves are getting a bit yellow, so I'm a bit confused here.

I have fed them 2-3 times since I switched to 12/12 which was 2 weeks ago.
Canna Terra (1/2 strenth) which has an NPK of 10-9-19 and Top Max which is organic.

Is it possible that they are deficient even tho I've fed them 3 times already??

Is it overfert?

I have enough dolomite in the medium to prevent calcium and magnesium deficiencies and the PH looks fine (never less than 6 or more than 7)

 

[Moppel]

looks like a ph problem. did you check your ph meter lately?

 

[Colliedude]

yeah I calibrated it 4 days ago
And shouldnt the dolomite keep the PH under control?

 

[Don Juan]

7 can actually be too high for pH. I think that you're going to want 6.2 - 6.4 or so. Since you're not using soil, you should double check that they're getting enough of what they need.

Do you have a PPM meter, by any chance?

 

[Colliedude]

No PPM meter I'm afraid
Should I adjust plain water as well because my tap water is always around 7,2-7,5. I always adjust it down to 6,4-6,6 but for some reason some people dont think that plain water should be adjusted...I never really understood why

But like I said, I have fed them 3 times in 2 weeks, shouldnt that be enough? I really dont get it...

 

[sproutco]

Optimum ph in soilless mixes is 5.6 to 6.2 Your mix is heavy. Next time leave out the vermiculite and add more perlite.

 

[Colliedude]

Ok so lowering the PH to 5.6 - 6.2 when I feed them nutes is what I should do?
What about plain water? Its always around 7,2-7,5, should I use PH down in this case as well?

So according to you this IS a PH problem?

 

[Guest]

Flush your plant

Flush your plant

Try plain rain or spring water for a week to correct the problem.

It might also just be natural yellowing of the lower leaves as flowering consumes a lot of energy..

..it basically looks like an underfert problem but since the top leaves are yellowing too... hmm

If nothing else works.. try feeding her more.

 

[Colliedude]

Aight I'm putting a bucket outside and hoping for rain

 

[CaptJamesTKirk]

and don't listen to sproutco - he's an poser, who poses as a grower but dosen't grow - - BEWARE

And gives neg K for pointing this out

over 3,200 posts since MAY 2006???

 

[Colliedude]

I couldnt care less about his personality or whether he grows or not. PH is not my area od expertise so I am thankful for all the advice I can get.
All the best,
//C

 

[Moppel]

if you not growing soil, ph 7 is way too high.

 

[Colliedude]

agreed, but where did you get 7 from? My PH is mostly around 6,2-6,5

 

[sproutco]

How many ml per gallon are you using with the ferts? You said 1/2 strength. We can put that in the calculator in my signature below and find what ppm your using.

 

[Colliedude]

awesome, I used 2,5 ML per litre/0,26 gallon

 

[sproutco]

I found another problem

I found another problem

Click on it to enlarge... Once larger put cursor in bottom right corner to get even bigger.


I entered 2.5ml per liter x 3.8 = 9.5 ml per gallon. Your nitrogen is 250 ppm. Very strong. This could be fert burn. You only want 100 ppm in flower. 100/250 x 2.5ml = 1 ml per liter or 3.8 ml per gallon you should use. I left the defaults of 1 and 1 on the calculator so this answer could be off a little. If you find net weight and total ml on the bottle you could enter those instead to get an almost perfect answer.

 

[Colliedude]

Thats about the most elaborate answer Ive ever received. Thanks a bunch brother!! Mighty kind of you to take the time and help a dude out.
I suspected overfert because my PH isnt THAT high. I mean it isnt OPTIMAL, but I had an eerie feeling that I had given them too much nutes (3 feedings in 2 weeks)
1 ML per liter it is then, and some of Atamis organic PK 13-14 during a couple of weeks.
All the best,
//C

 

[sproutco]

You should feed them with every watering but with the reduced new rate. Adjust the ph of the fert water after mixing for best results. 5.8 ph when using soilless mixes. Be careful not to overwater with all that peatmoss. Like I said before you can experiment with the calculator when you get net weight in grams off the bottle plus total ml of the bottle. You would enter those instead of the default setting which is 1 and 1. It will only come out stronger...maybe even up to 300 ppm n with the previous rate.

 

[Colliedude]

Coolie, will do, thanks

 

[Colliedude]

no net weight/total ml info on the bottled or anywhere else for that matter...sucky