leaf stress under bright light

[jguit]

Dude, save money and fix your problem by…..ie Reservoir capacity is 25 gallons, set feed strength, as the reservoir depletes, top off with Ph water only, when you have added 25 gallons of top off or the equivalent of your reservoir size, or 1 week of time expires, make a new batch!!! Topping off your reservoir with the same strength feed solutions is costly and problematic! Simply adding PH water will fix your ills.

Keep in mind, he's running DTW. Nothing wrong with adding same strength feed to the reservoir.

 

[phxazcraig]

Keep in mind, he's running DTW. Nothing wrong with adding feed at the same strength to a reservoir.

I'm absolutely not worried about saving money on nutrients, at least not with this grow! Yesterday I was running out of buckets to hold runoff. I dumped seven 5-gallon buckets full of runoff onto various outdoor plants and trees. I'd guess I'm way above 10-20% runoff, but it's awfully hard to tell. I need some sort of flow meter to stick in the line to measure input better, but it seems 4 gallons of runoff a day for four 3.5 gallon pots maybe a bit much.

Anyway, that's all an experiment in watering and feeding based on trying to keep EC from building too much in the root zone. I'm wondering a lot about cal/mag at this point because the leaf symptoms seem to look a lot like a calcium deficiency. Trouble is, it seems like a lot of stressed leaves look about the same (to me).

So here's a question - if I have a slight cal/mag deficiency coupled with lighting stress, would the symptoms only show on the brightest leaves without showing on leaves off to the sides or lower in the canopy? I wish I had a perfect grow going - I see wonderful pics of flowering plants with no leaf stress at all here - but I don't know if I made any mistakes other than having the light too close.

As an aside, the stems on the colas are very very strong - I'm not sure how easy they would be to bend over at this point. (Wouldn't help either, because it's the lowest part of the canopy in the center that needs more space.) I think I'm seeing the effects of silica and some plant training I did earlier. A month ago, and more, I was 'massaging' as many branches as I could reach and crushing the stalks between my fingers. (There is a defoliating video somewhere around this site that shows the technique.) As the stalks healed, they became much stiffer and stronger. The analogy was made in the video that a broken bone never rebreaks at the same spot because it's stronger than ever where it healed. I don't think I'm going to have a problem with heavy buds breaking thin stems.

While I haven't got any pictures of it, the middle of the canopy is just growing buds down there in the shadows at a goodly rate. I part some branches and stick my face into the canopy to see what is 6 inches down, and there are just buds growing everywhere! All new growth too - white pistils everywhere and small buds getting bigger and fatter. This may be the coco difference I've not noticed until now. The 'hidden growth' below the top layer. I have a feeling there is going to be quite a heavy harvest from the lower canopy areas. And even though I lollipopped before flowering, I've got little buds coming out all the way down to the coco now. And I might add that the canopy is so think that the area below the canopy is in deep deep shade. There is tremendous leaf mass that I did not defoliate, and I have to think it is helping now that those top leaves are burnt and (probably) inefficient. I think they are doing as much good providing shade now as anything.

 

[dbrzz]

Keep in mind, he's running DTW. Nothing wrong with adding same strength feed to the reservoir.

Nothing wrong doing that I agree. However, if your ec is rising, adding more nutrient solution is wasteful and unnecessary.

 

[phxazcraig]

Nothing wrong doing that I agree. However, if your ec is rising, adding more nutrient solution is wasteful and unnecessary.

Yes, I agree. However, it's more like trying to maintain a constant EC level without big swings, much like hydroponics. My runoff EC IS rising, and I've tried a lot of different things to manage it, but none to my satisfaction more than simply pumping more volume through the pots. I've lowered the light level, and overall everything seems better, even near the corners. I've changed to late bloom nutes, and the flowers are really putting on weight now. The lower flowers are growing at an amazing rate, even 3 feet below the canopy. I'm trying to lower the EC overall, but I happened to overdo the cal/mag a bit on this last reservoir fill. Leaves seem better, or not any worse. With the lower EC over the past week or so, I've seen an elimination of new tip burn, judging by new calyx growth.

If only I had flipped a week sooner to manage the height better! I'm 6 foot 2, and the buds are right at eye level. This coco grow has been amazing. I can't wait to see how the harvest goes. I just finished week 7 in flower, and it does indeed look like there is another 4 weeks to go on this strain. (Sour Diesel) If so (4 more weeks), I can't imagine how big the buds will be.