Yellowing / Lighter yellows - what gives?

[MIGrampaUSA]

So upon transplanting a clone from 1/4 gallon to 1 gallon into my soil mix - I fed with a half dose of BioBizz root juice and added citric acid to get to PH 6.8 - the run off came out at 5.8.

What's ideal run off ? I've done a bit of reading and found different theories...

I like to see my run-off change no more than .20. For example, if my water/nute solution is 6.5 pH going in, I don't want to see it drop more than .20 down to 6.3pH ... if it drops to 6.2 pH ... I'm ok with it. If it drops more than that my soil is out of range. It never rises so I have yet to worry about that. Here's my theory ... this has not been proven to my knowledge, nor have I spent time researching it ... If my pH swings much more than .20-.30 then something is buffering it down and my theory is it's the peat in my soil driving it down.

I use Fox Farm Ocean Forest, which is supposed to be buffered to approximately 6.5 pH. It usually starts acidic and over time the buffering kicks in. If my run-off is dropping below 6.0, I give the soil a good flush. After a week or so and sometimes another good flush, the pH begins to rise back up to the range I like it in. If the soil is too acidic, you'll likely see a cal/mag deficiency as those nutrients are not absorbed very well by cannabis in soil that is lower than 6.0 pH.

This works in Fox Farm. I have not attempted it in any other brand of soil. Fox Farm comes already buffered with dolomite lime, although I think I'll be adding some more to the mix next grow. My current grow had a rough patch due to cal/mag deficiency. I fixed it before I flipped to 12/12 but my plants are a bigger due to the delay and I may end up having to move 3 of the plants into my other tent.

 

[elduderito]

I'm using biobizz allmix soil which I think is quite similar to FF. I am re-using my soil - I re-ammended the soil with EWC, horn meal, guano and perlite...

If I continue seeing such a change in PH in compared to runout I'm guessing I should add some lime to increase soil PH? I will continue to monitor as this reading was just after repotting ...

 

[MIGrampaUSA]

I'm using biobizz allmix soil which I think is quite similar to FF. I am re-using my soil - I re-ammended the soil with EWC, horn meal, guano and perlite...

If I continue seeing such a change in PH in compared to runout I'm guessing I should add some lime to increase soil PH? I will continue to monitor as this reading was just after repotting ...

Not garden lime. There's a huge difference between garden lime and dolomite lime and they should never be considered to be the same/substitute-able. Garden lime will cause more headaches. It could easily have your soil pH at 8.0 or higher due to uncontrolled buffering. Dolomite lime won't likely adjust your soil beyond 6.5 even if you use too much by accident.

 

[elduderito]

still seeing these same problems on this one particular Karma Haze plant ... the rest of the garden seems to be fine... started around day 30 of flower... Mg? I know I used to read a lot about people using epsom salt in week 4 of flower...

 

[elduderito]

bump... I haven't fed much nitrogen at all - I think the clawed tips appeared at transplant and there hasn't been any new growth showing the claw --- maybe hungry for N ??

 

[elduderito]

still nobody?

 

[Oldchucky]

Did you go to the infirmary category and check out the sticky, charts? There’s a lot of stuff in there that deals with leaf Issues and nutrition. Might pick up a lead there.

 

[elduderito]

Did you go to the infirmary category and check out the sticky, charts? There’s a lot of stuff in there that deals with leaf Issues and nutrition. Might pick up a lead there.

I still have to check PH run off - but on the basis that this is a plant specific issue I'm leaning more towards N deficiency... I tried correcting this on the last run, but maybe it was too little too late ... I'm gonna give 0.5 - 1ml (per litre) BioGrow next watering and some aloe vera next feed....