flower development stops

[theother]

Am having a bit of an issue where flower development seems to pause and stop every time at between 3 and 4 weeks. Flowers develop well but just don't seem to swell, they ultimately mature fine but they just don't swell up the way I am used to. Every other part of the cycle seems perfect, stretch is unreal, they come in at about 12" tall and stretch to the net which is set at 36".

The environment seems ideal to me, they are drip fed dtw with plenty of runoff, I use drip clean in everything they are fed 3 times a day to begin with and peak at 5 times a day, co2 is set at 1500 ppm, ambient temp is 81 canopy temps vary between 79-85. humidity starts about 65% and is lowered to 55% as the cycle progresses.

Nutrients are canna AB, Hydroplex, Big bud dry, and magnesium sulfate. PH is always 5.8-6.0 Generally they are fed at around 1.3 ec (7 ml's AB 2 mls hydroplex, .5 grams Big Bud Dry, .5 grams epsom) this comes out as

75
65
114
36
30
83

I was comfortable with this because I felt like it was close enough to the H3ad numbers to be safe. It seems as though they like it quite a bit for most of the cycle. I do begin to raise those until I hit my absolute peak of (8 mls coco AB, 6 mls hydroplex, .5 grams epsom) which comes out at around 1.8 ec and gives

85
106
132
44
17
95

I use RO with enough tap to bring the EC of the starting water to around .2-.3

There is absolutely nothing wrong with the way the plants look, ZERO signs of any discomfort, no signs of burning, they look well fed runoff seems to be perfect (PPM drops (between 100-200 ppm @500), PH raises to maybe 6.2 in the runoff)

What really screws with me here is everything looks fantastic the entire time, they just don't swell, stretch is perfect, flower set is ideal, they stack up nicely, they swell for a bit but they just seem to poop out at that point. Making me truly insane because it is impossible to show these bastards anymore love and care than I am already.

The weakest part of my current system is really the cleaning of the plants, they are flipped small so its pretty pointless to clean them up before flip, they stretch fantastically and somewhere around week 2 I begin to slowly clean them up. I do just a bit each day, removing branches that don't reach the light, cleaning up lower new growth. Really minimal removal each day, spread out over a long period of time. I have experimented with not cleaning them up and it does not seem to help the issue of flower development slowing and just creates tons of larf.

They are also spike fed guano and carbs (florilicious plus) and tricantonal (GPW massive) Phd to 6 as a minor flush with 50% runoff twice a week. Their scheduled feedings kick in immediately afterwords so their should be no issue of them becoming deficient after that flush.

 

[medicalmj]

First thought was that you may be using a product that prevents senescence in the plant. That is act of growing old and dying. Many products contain growth hormones or natural products that stimulate growth regulators. I see you are using both flora+ and tricantonal. Flora+ contains seaweeds, which contains cytokinins. Cytokinins are used to help promote tasty flowers but also will prevent senescence. Don't discountinue stuff like floralisciuos+ but just know when to stop if you want the plant to "die". And tricacantol is a very powerful growth stimulant that can double your flower set. However, the studies I read didn't indicate when or if, to discontinue for proper senescence of the plant. So those are two possible culprits to investigate. Good luck!

 

[theother]

First thought was that you may be using a product that prevents senescence in the plant. That is act of growing old and dying. Many products contain growth hormones or natural products that stimulate growth regulators. I see you are using both flora+ and tricantonal. Flora+ contains seaweeds, which contains cytokinins. Cytokinins are used to help promote tasty flowers but also will prevent senescence. Don't discountinue stuff like floralisciuos+ but just know when to stop if you want the plant to "die". And tricacantol is a very powerful growth stimulant that can double your flower set. However, the studies I read didn't indicate when or if, to discontinue for proper senescence of the plant. So those are two possible culprits to investigate. Good luck!

Very much appreciate your response, it is insightful and thought provoking. I really had not considered senescence as they seem to mature and finish out, however I do honestly believe you are onto something. when I think about what they look like throughout the cycle they seem to stick in a period that I would describe as stacking, the vertical growth does stop eventually, and that is pretty much where they stay.

You are really making me think about my experiences with tria. I suspect that tricantonal may react differently in hydro root environments as opposed to soil. I had great results using it in peat based soils but when i honestly think back, every run that has used it in coco or flood and drain has had a similar issue to what i am describing here.


Appreciate your thoughts very much, the flora+ is gone this week as they are at 5 weeks and I don't usually use it during late flower. I will discontinue tria as well, no harm in experimenting. I think next run I will spike it only during weeks 2 and 3 with tria, or possibly cut it out all together.

I will give them a healthy flush with diluted nutes and discontinue the tria and the flora+. Any advice as far as kicking them back into a normal life cycle?

 

[Snow Crash]

Your nutrient lineup looks fine to me, but your numbers seem a little off.

7ml of A+B, 2ml of Hydroplex, 0.5g of Big Bud Dry, and 0.5g of Epsom should net you:

N: 95ppm
P: 65ppm
K: 116ppm
Ca: 84ppm
Mg: 46ppm
Su: 15ppm+

I find that cutting out the Nitrogen and Calcium from the base system a little more, and increasing the Potassium levels from where you're at (up to 200ppm) is what has worked best for me in coco during days 25-40 of flowering. I will drop my base to about 5ml/gallon around this period of time to help there.

For potassium I have been using Green Planet Dense 0-0-62. When cutting the base down to accommodate the N:Cal decrease I usually need to up the Epsom a little. 0.6 to 0.8 grams per gallon does the trick there.

Check your numbers again, I think if there's a problem nutritionally its because you're a little off from where you think you are. But like you say, plants are looking healthy. Maybe up you EC a smidge, with all that CO2 floating around I'm sure they can handle a higher EC than my non-enriched plants.

 

[Granger2]

Medicalmj IS on to something. I'd also cut the CO2 back to 1200 max and turn it off or set it at 500 after week 5. Good luck. -granger

 

[theother]

Your nutrient lineup looks fine to me, but your numbers seem a little off.

7ml of A+B, 2ml of Hydroplex, 0.5g of Big Bud Dry, and 0.5g of Epsom should net you:

N: 95ppm
P: 65ppm
K: 116ppm
Ca: 84ppm
Mg: 46ppm
Su: 15ppm+

I find that cutting out the Nitrogen and Calcium from the base system a little more, and increasing the Potassium levels from where you're at (up to 200ppm) is what has worked best for me in coco during days 25-40 of flowering. I will drop my base to about 5ml/gallon around this period of time to help there.

For potassium I have been using Green Planet Dense 0-0-62. When cutting the base down to accommodate the N:Cal decrease I usually need to up the Epsom a little. 0.6 to 0.8 grams per gallon does the trick there.

Check your numbers again, I think if there's a problem nutritionally its because you're a little off from where you think you are. But like you say, plants are looking healthy. Maybe up you EC a smidge, with all that CO2 floating around I'm sure they can handle a higher EC than my non-enriched plants.

You were absolutely right, I was off in my input of the guaranteed analysis of the cocos a&b, had missed 1% N. The numbers you posted are correct, I still can't figure out where I missed the 2ppm of K that you show, but I am going to go back to the drawing board and re enter all guaranteed analysis from scratch. That was a pretty decent mistake on my part!

I will up the K a bit too, and see if that helps, I can accomplish it pretty easily by diluting the res and adding a bit of BB powder (will do the math on it tonight when I see how much is in the res.

As far as the problem goes, I am sort of at a loss. It is complete stop in development. I have seen it once before on my last coco run and it absolutely stopped around week 3 and never bounced back. The weirdest thing is the plants look healthy for all intents and purposes, the development just stops and they finish off like that.


I am forced to start looking at environment. The only thing I can really think is that possibly it is a bit of VPD? I have maintained 55-65% humidity and the canopy temps have been between 79-83, they swing through that range until an exhaust fan kicks on and drops it down to 79. This happens more frequently at the beginning of the night (higher outside temp) and then pretty much sits stable for much of the night. The co2 will drop to 1000 ppm when the fans are on for a couple minutes then bump back up to 1500.

I moved a couple plants in that are just getting flipped and they look healthy (I actually put them in there just to get an idea of what it looked like, as I am used to seeing the effects of VPD on plants in veg) unfortunately it didn't answer my question as they are quite perky, sitting up praying for light and blasting along. This leads me to believe that VPD is not the culprit. It is also a very good visual aid of my problem (fantastic veg, stretch, early flower, and non existent late flower development)

I am truly confounded by this, for the most part the environment is the best money can buy, the nutrients are very close to perfection (if not perfect, certainly not enough to cause an issue such as this). I can say without a doubt I have gotten stellar results with an environment much worse than this.

Unfortunately because I have gone through this before, i know what to expect and they will just sit as is until I decide enough is enough and chop them (unless someone has some insight).

It is absolutely beyond me how a set of parameters (environment, nutes, air movement etc) can produce such explosive growth through out all other stages of life and then come to an absolute screeching halt at the swell phase. All I can think is it has to be something peculiar to coco (and possibly flood and drain as I have experienced something similar with that system). I do have my eye on tria as a possible culprit as that has been added right around the time everything stops both times (could well be a coincidence though, I am definitely leaving it out from now on and on the next batch)

I am open to most any suggestion as this has now gone from an isolated incident (happening once) to now being an epidemic.

Also I should add that this seems to be an across the board problem evidenced by the fact that plants which progressed faster stopped at a further along state of growth and the suckers reaching up at the edges stopped right mid stack. It is interesting as it is kind of like a cross section of where everything was at about a week and half ago.


I will be a much happier and healthier human being when i put this behind me, to be honest it is kind of my worst nightmare seeing it happen again. I had a lot of things I blamed for it happening last time, but this program is so much more advanced I have very few culprits in mind. The across the board slamming to a halt makes me suspect something in the root zone being the culprit, as the more advanced plants managed to get further along than the less advanced (ie not so much something wrong with ratios stopping everything as it reached one set point of growth, more like something I fed to all that stopped the whole thing).

 

[theother]

is it possible that 5x a day is too much irrigation? TBH I really can't say if it is a proper amount because they have stopped both times I changed the schedule up that high (quite possibly just a coincidence). I have definitely seen 3x a day work flawlessly, the switch to 4x doesn't seem to hurt they usually move fine through that period. I have read many times that 5x can be the sweet spot, however I am beginning to wonder if that is a bit too much. Don't see any of the signs of over watering I have seen in soil, but again its coco so hard to say.

I have the timings down quite well, first water produces maybe 5-10% runoff and it goes up from there until the last watering produces runoff closer to maybe 30%

 

[Snow Crash]

How old is/are the bulb(s)? Any chance you might be due for a replacement?

Dirty glass or reflective material could be cutting your umols down 10-15%. I hear about this commonly from people. Everything's the same from one run to the next, but then the production dips off for some reason. 9 times out of 10 is a bulb late in it's 2nd or 3rd runs that just isn't pushing the ppfd that it used to.

Just to think outside the reservoir a little.

 

[Elements001]

I'm no expert by any means, but I've been reading up on Broad mites lately, and I noticed a recurring pattern where people noticed the plants would kind of stop right around where you're at, then later they would fill out and finish maturing. Some people would post about how their plants would still look fine, they just had that stunt in growth in mid-flower that wouldnt pick up until towards the end again. I don't know if it's possible you could have them in your setup, but it's just something that popped into my head. I hope this doesnt offend anyone, just trying to throw ideas out there.

 

[Asslover]

Back down your feedings to 3 or even 2 waterings...

 

[theother]

Really appreciate everyone chiming in, feel free to throw any other thoughts out here, I feel like i have learned some things in this thread. I am gonna institute everything mentioned here and will definitely post updates. Particularly on future runs.

How old is/are the bulb(s)? Any chance you might be due for a replacement?

Dirty glass or reflective material could be cutting your umols down 10-15%. I hear about this commonly from people. Everything's the same from one run to the next, but then the production dips off for some reason. 9 times out of 10 is a bulb late in it's 2nd or 3rd runs that just isn't pushing the ppfd that it used to.

Just to think outside the reservoir a little.

That is fantastic advice, i have been down that road before! The bulb is brand new hortilux eye hps. Old bulbs are the worst! cost the same to run as a fresh bulb. I do run the bulbs twice, hope thats okay, let me know if its not. Ready to go DE and get more than 2 out of each one! Really excited about the whole switch to DE.

I'm no expert by any means, but I've been reading up on Broad mites lately, and I noticed a recurring pattern where people noticed the plants would kind of stop right around where you're at, then later they would fill out and finish maturing. Some people would post about how their plants would still look fine, they just had that stunt in growth in mid-flower that wouldnt pick up until towards the end again. I don't know if it's possible you could have them in your setup, but it's just something that popped into my head. I hope this doesnt offend anyone, just trying to throw ideas out there.

Interesting, BM's scare the crap out of me! I doubt very much they are in here, but I will step up my inspections, specifically looking for the egg sacks, I think scoping under leaves is probably my best bet at catching them?

IME with what I am running, it is unlikely that this cut will surprise me and start swelling. It would be amazing if it did, but I think generally people who can get back on track are running longer sativa dom hybrids. A bit more room for forgiveness there. These are at 35 days and cut is usually done at 50, anything more is strictly to change the effect of the medicine.

Back down your feedings to 3 or even 2 waterings...

I think this is the answer, it is the one thing (besides the tria) that changes at the exact time period that is punishing me. Will absolutely cut it back substantially. I may be the first person in history to over water coco.....DOH, lessons learned I guess.

 

[stihgnobevoli]

I may be the first person in history to over water coco.....DOH, lessons learned I guess.

doubtful. got any pics? i wanna see the plants so i can know what to look for.

 

[theother]

doubtful. got any pics? i wanna see the plants so i can know what to look for.

They look like incredibly healthy happy 25 day flowering plants....the problem is they are 35 days old Pictures really wouldn't help much man, unless it was a photo a day showing the growth and stagnation (which I may well do next round, because its almost comical when they slam to a stop)

Believe me I would have said the same thing you are, if I hadn't seen it happen twice. There is still the tria to look at as the culprit, however I am somewhat doubtful that could have this drastic of an effect. I have seen it utilized successfully in many different systems. and the worst thing I have seen it do is kind of larf out a couple of runs for friends of mine, for the most part it is a good addition to most gardens, however I don't think you will be seeing it around mine for awhile as I am just not going to be taking any more chances.

I can outline the program a bit to see if that would help you determine if this is something that may be a risk in your garden. Again I have no idea if it is actually overwatering, however it is starting to seem like the most likely culprit, two separate runs, two separate cuts, same soul crushing stop to flower progression. It may be that I am way over irrigating as opposed to what some of the old pros would do. I usually figure about 5 gallons a day goes out of the res, and that really doesn't change when I up the feedings, I just turn down the cycle timer from 15 seconds on 1 minute off, to 11-12 seconds on, 1 minute off. the timer that the cycle timer is plugged into is on for 3 minutes, so they get the 3 cylces of 15 second waterings (I really like this as it gives the solution time to move through the media and allows me to accurately judge when runoff has been achieved.

They are in two gallon pots (either smart pots or plastic, haven't noticed much of a difference yet) They go from a 2 week veg (feed, wait three days, feed, wait two days, feed wait two days, (roots are starting to blow out the bottom at this point, water daily until flip) Once they are flipped they start at 3x feeds a day and they are gradually upped to 5x right around day 25-30 (should be when this cut is swelling). They are watered using a drip manifold feeding 2 drippers per pot, center plants have 3 drippers, 12 plants in a 4x4 tray.

They stretch from 8-10" to about 36" with an indica. Absolutely the healthiest veg, stretch, stack I have ever seen.

Really the only downside I have seen to the veg stretch program I have going here, is they grow so fast that cleaning them up is almost a daily occurrence, I start when they hit the net, and just do a small amount of work each day, so no plant ever has too much removed. If anyone has some ideas here I would be into it, used to clean before flip and maybe once after a while, but with this program I don't see how that could ever work as they move so quickly and come in so small it would be a joke.


Nutrients is kind of complicated, it is a mix of Coco A&b, hydroplex, big bud powder, epsom salts, and a bit of calmag plus during veg. The feed schedule is sort of a bastardized hybrid I have come up based on h3ad's modified lucas, and sort of morphs into snowcrash's profiles. Everything is figured out using the canna stats calc.

I under no circumstances take credit for designing the nutrient profiles, nor do I claim to know that this is the only way to feed coco, however I think it is safe to assume that they are pretty close to optimal, as we can all pretty much agree h3ad was onto something with his formula, and snowcrash has some of the most insightful ideas I have seen so far. I am sure I have periodically screwed things up along the way, however I have been gardening long enough to know that without a doubt these plants should THRIVE on this schedule. However they just slam to a stop.

I have no explination for why they would react the way they are,. The only thing I can think is most of the guys who are advocating the 5x schedule (think HGO and others) are running vert rooms with maybe 6 plants surrounding a bare bulb. Since I am running an air cooled 1k over 12 plants, it may be that they just hit a point after stretch where they can't handle the extra water? I am reluctant to say I will turn it down below what I run them at when they are 10' tall, but I will certainly take it back to the 3x feedings, and if that doesn't work i will go even further down. Possibly as the plant diverts its way away from vertical growth and focuses on the blossoms it needs a bit more of a wet/dry cycle? I really don't know just thinking out loud.

 

[Asslover]

I don't think you're over watering per se, but unless your pots are absolutely packed with roots then i think 5x a day is too much. Remember, roots in coco get more oxygen when the coco isn't so water logged. By my way of thinking, unless the pots are packed with roots (and I mean PACKED!) then you're not giving the plants enough time to "catch there breath" before soaking the coco again.
All speculation, of course, but you certainly won't have any adverse affects by cutting the waterings down to 2 or 3 X VS 5X...

 

[Granger2]

Have you checked your roots? It could be that they've never had to root out thickly cuz they're getting watered so often. Then they reach a point where the proportion of roots to foliage is maxed out, and the roots can't support more foliage/blooms. Do you use a root stimulator?

I'd cut back watering to only when the medium is noticeably lighter then water/feed to 30%+ runoff, then wait again. Use a good root stim [Rhizotonic, Roots Excellurator, GO BioRoot]. Good luck. -granger

 

[theother]

Have you checked your roots? It could be that they've never had to root out thickly cuz they're getting watered so often. Then they reach a point where the proportion of roots to foliage is maxed out, and the roots can't support more foliage/blooms. Do you use a root stimulator?

I'd cut back watering to only when the medium is noticeably lighter then water/feed to 30%+ runoff, then wait again. Use a good root stim [Rhizotonic, Roots Excellurator, GO BioRoot]. Good luck. -granger

I do use a rapid start during the two week veg at 2.5 mls per gallon, have had great luck with this program, seems to blow the roots up super fast. I add it to the first res at 1 ml per gallon and just a splash to the second, no more after that. I haven't removed any of the these to check the roots, I can only assume they are rooted quite well. Every time I have removed them from pots they have been rooted insanely well in the past.

 

[Snow Crash]

Just to keep the thought train a'rollin with the watering schedules...

During flowering, and especially at that transition to heavy flower set, the hormones that the plant produces to signal cell growth changes. The hormones needed to encourage new and healthy root growth are sacrificed for those that encourage flower growth. It could be that the root system reaches a point where the heavy waterings aren't beneficial because there's a layer of dead cells that needs to be "shed" from the root system so that the "raw" and viable root cells beneath that layer can be exposed to the fresh nutrient solution. It's not so drastic as to cause a deficiency, but it's enough of a loss to prevent serious flower stacking.

This is the intended purpose for Cannazym, but I think that a few good organic tea feedings should introduce enough beneficial bacteria and enzymes to avoid any serious cost. I've been incorporating the occasional OG Tea between feedings without issue.

As much as I do tinker with my NPKCaMgSu levels in bloom, I also like to play around with root supplements through veg and into flowering. CX Nutrients Regen-A-Root is ideal for mid-late root supplementation when you are dealing with some kind of Pythium or root rot. I used this on my last run just once a week through day 45 of bloom and I certainly saw improved performance from the plants after doing so. I never like to suggest solutions from a bottle... but yeah, we're all just kind of guessing here anyway.

Edit: LOL - Granger beating me to it! I shouldn't take so long to finish my replies.

 

[theother]

Looked back through everything and I think I do have enough pictures to kind of tell the story. I am a little weird about posting pictures, so if these end up disappearing its because they gave me an anxiety attack.

1 week

18 days

5 weeks

5 week sideshot 1

5 weeks sideshot 2

Those sideshots are by no means the largest in there or anything, they were just tall and easy to get a picture of. Wish I had some pictures between 18 days and 5 weeks, if this happens again I will definitely document the stall for help diagnosing.

Also some may look at these and not think anything is wrong, I know the cut, its not an easy cut, but it is quite possible to chunk it out. it definitely shouldn't look like this. Its no sour d but its no slouch either.

 

[theother]

Realized I didn't include these pics with the last post. I checked this morning and noticed a bit of leaf curl that i don't think i have seen before. It could well be a result of the RH dropping to 50% with the slowed down feedings. At 78-82F (might ocasionally peak at 83) I feel like 50% is too low, gonna have to take some corrective action.

Here are some pics of what I saw

Also it should be noted that there is something hot quite close to these leaves, they may be running a couple degrees above max canopy temp, I can check with IR if it seems pertinent. I do everything I can to keep all areas perfection but sometimes there are some unavoidable heat sources.

Just to keep the thought train a'rollin with the watering schedules...

During flowering, and especially at that transition to heavy flower set, the hormones that the plant produces to signal cell growth changes. The hormones needed to encourage new and healthy root growth are sacrificed for those that encourage flower growth. It could be that the root system reaches a point where the heavy waterings aren't beneficial because there's a layer of dead cells that needs to be "shed" from the root system so that the "raw" and viable root cells beneath that layer can be exposed to the fresh nutrient solution. It's not so drastic as to cause a deficiency, but it's enough of a loss to prevent serious flower stacking.

This is the intended purpose for Cannazym, but I think that a few good organic tea feedings should introduce enough beneficial bacteria and enzymes to avoid any serious cost. I've been incorporating the occasional OG Tea between feedings without issue.

As much as I do tinker with my NPKCaMgSu levels in bloom, I also like to play around with root supplements through veg and into flowering. CX Nutrients Regen-A-Root is ideal for mid-late root supplementation when you are dealing with some kind of Pythium or root rot. I used this on my last run just once a week through day 45 of bloom and I certainly saw improved performance from the plants after doing so. I never like to suggest solutions from a bottle... but yeah, we're all just kind of guessing here anyway.

Edit: LOL - Granger beating me to it! I shouldn't take so long to finish my replies.

Just caught this post, I do agree with this, I have contemplated running cannazyme as an included addition to the lineup and just take a bit off the hydroplex to accomidate the PK thats in there. I think it may honestly push the costs up too far as I am super poor. I have the cost of most of these res fillings to about $6 which I find quite palatable.

I do run teas every 2 weeks a couple days after the flush i do every two weeks. I also feed twice a week from a seperate res that includes guano (liquid budswell) some carb (floralicous+) some mykos (greatwhite) and it used to include tria (GPW massive) think I am going to discontinue tria for the foreseeable future just to see if that could be a contributing factor to the flower stall out. I honestly feel like the root zone should be quite alive and that is for the most part backed up by the stellar growth throughout the rest of the cycle.

Really the two things that happen differently around the slowdown are the increased feeds (which are now gone) and the tria (which is also gone)

Really don't have any hope for seeing much this round, but there are always more and resolving this issue is currently the top priority for me.

 

[theother]

J.

Thought I should take the opportunity to run this past you, how does this look for a 5-6 week res to you.

6 mls AB
6 mls hydroplex
0.7 gram epsom
1 gram Big Bud powder

I am coming up with
N 82
P 116
K 202
MG 46
S 54
CA 71

I am seeing this as a 1-3-3 (approximately) ratio once I add back the oxygen to P&K

I think its going to be near impossible to hit the phos dominant ratios with the nutes I currently have on hand, without going like 10 mls per of hydroplex (what scares me their is the additives, not sure they would be safe at that concentration) I am just still kind of gun shy of swapping out the base, as so far I have very much enjoyed the clean qualities of the canna meds. I know I will have to bite the bullet eventually and swap out for ripe or something similar, will make it much easier to hit the ratios.