Help with diagnosis please. opinions appreciated.

[Frankster]

Note the little brown spotting, but more obviously and concerning is the coloring along the leaf edges and tips.

Alright, everything was doing fine and I'm probably 2 weeks into flower, so this is the time these things usually happen for me. If nothing else, the timing is predictable.

Anyhow, let me know your thoughts. The plants have been aggressively pushed.

Things I've done. The last day or two have been flushes. I've been really close to the lights, so I backed them off thinking intensity was a possible issue. pH should be pretty good at around 6.5


My guess is potassium deficiency, but these seem difficult to nail down.

 

[Dirtbag]

Looks possibly calcium deficient. Whats your starting water and nute line?

 

[Frankster]

Looks possibly calcium deficient. Whats your starting water and nute line?

RO and/or using Dehumid distillate. Yea, I was thinking the same thing a few days ago, So I've been hitting them regular with calcium carbonate and magnesium sulfate, thanks dirtbag, that reassures me that I'm on the right path.

I was almost thinking it might be something else, or a few things going on here. always such subtle differences in appearance. Seems to be effecting mostly the new growth only, and I'm seeing a narrowing of the newer leaves. It's certainly affecting my growth rate, so I want to get this right straight away.

Personally, I was thinking maybe my first assumption about calcium was wrong and it might be potassium, but now I'm still unsure.

Much of my nutrients have been added as amendments early on, so I'm thinking now that it's started flowering, I'm going to have to adjust it from here forward. I might go back to using more fossilized bat guano with this grow, I haven't really thought that far ahead yet, but that's likely the plan.

I've been playing around with a lot of different salts of late, mono and dipotassium phosphate, potassium hydroxide, and various bicarbonated salts trying to learn and broaden my experience. Anyhow, I really like the results with the guano, just a few minor adjustments need to be done toward the end.

 

[RR1]

Note the little brown spotting, but more obviously and concerning is the coloring along the leaf edges and tips.

Alright, everything was doing fine and I'm probably 2 weeks into flower, so this is the time these things usually happen for me. If nothing else, the timing is predictable.

Anyhow, let me know your thoughts. The plants have been aggressively pushed.

Things I've done. The last day or two have been flushes. I've been really close to the lights, so I backed them off thinking intensity was a possible issue. pH should be pretty good at around 6.5


My guess is potassium deficiency, but these seem difficult to nail down.

If you are using Cal/Mag, go up. If you are not, start. Cannabis love calcium and magnesium. Also, about every 10 days I spray my plants with 1 tsp/gal of epsom salt/water. It is magnesium sulphate, and plants like it.
RR1