Holy nute deficiencies, Batman!

First, I'll admit I'm not sure if I should post this here, or in the hydro forum, but here goes.

Grow Details -
DWC Drip Feed Hydro system
Lucas Formula - GH based nutes - flowering profile - 750ppm
pH - 5.6 and stable
6 - 42w "soft-white" CFL's over each plant; 2 - 26w "soft-white" CFL's in front
Room Temp - 77 average; 80 high; 72 low
Res Temps - 74

I'm in the home stretch as far as flowering goes. Based on the breeder's timelines I *should* be harvesting in 1-2 weeks. I know that it's somewhat common for a plant to self-cannibalize during the last couple of weeks of flowering, but what I'm seeing seems a bit extreme.

Depending on where I look, my plants are showing symptoms of phosphorus, potassium, and calcium deficiencies. Some of the damage is left over from when I had my heat problems a couple of weeks ago (http://boards.cannabis.com/plant-pro...ed-leaves.html) but some of it - especially the potassium deficiency - is new.

Heat shouldn't be an issue. The room is staying in the 70's (72-79) and the reservoir temp is 73.

pH stays between 5.6 and 5.8.

I've checked for root rot. The roots look good. No bugs or visible mold/fungus.

The only thing that's changed is that, based on the advice of a couple of growers, I've backed the nute strength down to 800ppm, instead of 950ppm. And because I got a bit busy this weekend, it actually fell to 750ppm before I topped it off last night.

Is this normal for late flowering?

Should I increase the nute strength?

Also, I know with soil grows it's pretty common to flush during the last couple of weeks and give the plants no nutes, and I've heard of some hydro growers doing the same. Lucas recommends against flushing when using his formula. Any thoughts?

Edit to add a P.S. On the plus side, the buds are starting to really swell up nicely and a lot of trichs are forming, even on some of the fan leaves. I looked last night with a magnifying lense and it looks like about 30% of the trichs are cloudy. So at least from a budding perspective, things seem to be going well.

Help....do you have an oscillating fan running and are you using hydroton? I've been fighting the exact same issues in my last few grows and can NOT figure out the problem. My ph is normal too....I check it all the damn time. Do you have any photos?

Edit: I'm using the botanicare nutes and my ppms are up around 1400 so I know its not a lack of available nutes.....although your numbers are lower than mine.

Ps....if your plants are eating the numbers down...i'd up the ppms.

Based on your conclusion of nutrient deficiencies, backed by the under 1000ppm nutrient levels, I would say you should increase your nutrient concentration. Some strains like it low, but if yours is not looking so well, I would up it. Shoot for maybe a 1200 at first; some strains love it upwards of 1800... trial and error :)

Also, consider changing out your whole solution. It's entirely possible your solution is full of only a few nutrients left over and is missing the macros (NPK) that you think you are missing.

:).

I dont know if this will help or not, but as an example, my DWC plants are on the Biotonicare starting at 1000ppm and looked like they were in a nute lock/def, i increased to 1200ppm and they did a nice improvement, almost immediately (within 24hours the ppms dropped 200), so i upped it to 1400ppm and the samething happened, almost immediately there was another nice improvement (24 hours later 100ppm drop) so i have just changed it to around 1600ppm and they are now getting the rich dark green leaf and bright center.... coming together nicely, but watching that nute drop for me was key.

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Originally Posted by Weedhound

Help....do you have an oscillating fan running and are you using hydroton?

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I don't have a fan running in there at all now, at least not full time. I did have a large box fan going, but I discovered that the fan motor was significantly adding to my heat problem, so I turned it of. Now I only turn it on for about 15 min in the morning and evening to exchange the air in the closet.

Yes, I'm using hydrotron.

No, I didn't have time to grab any photos this morning before work. Sorry, I know how much that helps in the "what's wrong with my plant" game.

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if your plants are eating the numbers down...i'd up the ppms.

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Yeah, I added nutes to the reservoir last night to bring it back up to 950ppm. Either my math was off (doubt it) or the plants were really hungry, because it was down the 870 this morning. I'll top them off again tonight and see what happens.

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Originally Posted by gainesvillegreen

Based on your conclusion of nutrient deficiencies, backed by the under 1000ppm nutrient levels, I would say you should increase your nutrient concentration.

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To be honest, I'm not sure that *is* my conclussion. I'm a new grower, so I don't trust my own instincts yet heh. That said, I've ruled out everything else I can think of, so that's all there is left. If anyone's got any better ideas, please speak up :).

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Also, consider changing out your whole solution.

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That thought's crossed my mind as well. Although, again, I'm really late into flowering - just 1 or 2 weeks left - and I know a lot of growers like to flush the nutes and let the plant feed on itself. Also part of the trick with the Lucas formula is that the nutes are never replaced, so that by the end of your grow most of your N has already been consumed and you don't need to flush. Replacing the nutes might be counter productive. I'm hesitant to add a completely fresh batch of nutes in, under the circumstances.

To all as an FYI:My TDS uses a 0.5 conversion, so 950ppm on my meter [email protected].

Thanks for all the input.

Those guys are right.....up your nutes. ;)

Help....a ps....Stinky mentioned to me that if a def occurs in the last two weeks of flowering she doesn't attempt to treat it. I did that with one of my plants with a potassium def in the last two weeks and it worked out fine.....fyi

NOW you tell me lol.

I upped the nutes back to 950ppm last night. It was back down to 870 this morning, so the plants were hungry. But that's the last of the nutes I'm gonna give them.

What day flowering are you at? Sure sounds like your plants have some growing to do.....eating down almost 100ppms a day? Don't have any photos do you?

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Originally Posted by Weedhound

What day flowering are you at? Sure sounds like your plants have some growing to do.....eating down almost 100ppms a day? Don't have any photos do you?

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I'm at Day 44 as of this morning. Per the breeder's info, they should be finishing up Day 49-56 (7-8 weeks) but for some reason my plants are finishing early. Took a look yesterday and the most mature plant was at about 80% cloudy trichs and about 5% amber. The other two aren't quite there yet, but they're close.

I actually harvested the first plant last night. I know it's still early by some growers standards, but I did that on purpose. My plan is to harvest the first one early, the second one in the middle of the window, and the third one late. Since I'm a complete newb smoker (first time was last week off a sample of my own grow :stoned:), I want to compare the effects of the different harvest times. I took clones of the two strongest growing plants, so next time I'll know exactly how long to let them flower for.

As for the nutes, I'm not sure they ate all of them that quickly. It's possible that my math was off and I didn't get the res all the way up to 950ppm (that was a math based guestimate). Usually it takes about 5 days for them to eat 50ppm out of the res, so this would be a bit unusual. Maybe they were just hungry after I let the concentration drop so low ;).

As for pics, I don't have any of them on this computer but there's a bunch in my grow log. It's on another forum...next grow log will be posted here, I promise! :D. Help_Needed's first grow - second attempt - Grasscity.com Forums

I hope you havent affected the taste, from adding ferts just at harvest time .........;)

It does affect the taste....and it tends to give me headaches if I haven't flushed my weed so you might want to get your aspirin out. ;)

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Originally Posted by Ganja Guerrilla

I hope you havent affected the taste, from adding ferts just at harvest time .........;)

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Well, since I've never smoked anything else before I'll never know, will I? lol

In honesty, if I'd realized I was so close to harvest I wouldn't have added the nutes. But everyone said to feed them, and I did lol. Then again, Lucas recommends NOT flushing prior to harvest with his formula and a lot of growers have said it doesn't hurt the taste, so hopefully it won't be too bad.

I've never heard of not flushing.....but don't use the Lucas formula either. Hope they give you some nice smiles.....good luck. :)