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[Yaboty]

2 weeks into the flowering stage

[Yaboty]

HELP!!

Leaves started looking like this after spraying with neem oil to fight septoria - i ignorantly used concentrated neem oil and then i rinsed it off after 2 days

[Rootsruler]

Yup! 2 weeks at least.

[Gingerbeard]

This is neither here nor there, but I am super curious how your bags and trays look almost brand new after growing those chunkers.
What are they?

[Bluey]

Not a leaf in sight. I'm guessing sativa dominant so a few more weeks by the looks of it.

No doubt the watering has dropped right off, you cut off all the leaves. If you had of left them on you could reliably tell growth rate from water uptake which gives you a good idea on harvest time.

[Shenandoah]

Hi all

Thanks for all the comments- super helpful!

I’m wondering if my plants are ready to harvest. I’m actually going out of town tomorrow (poor planning with the timing). So I can either harvest now, or in about a week. There still seem to be a lot of white pistols, especially in the lower branches, but in other parts they’re almost all curled up. I don’t have anything to magnify the trichomes, can’t tell if they’re clear or white.

What do you guys think?

[Bluey]

I did it to stop the coco from drying out.

I'd only do it as long as you can keep humidity down. These girls had a canopy of about 9' x 6', and hardly any defol. They were big.

When I dropped temps from 23⁰C to 22⁰C in mid to late flower the water uptake dropped a lot as humidity didn't drop much as 40% was as low as I could go at those temps with 5 huge plants.

Dehumidifiers that work well at 22⁰C are very expensive, mine couldn't go below that temp without issues.

[Rootsruler]

Do you think lights out feeds are ok? I was told the plants change up processes at lights out and uptake is reduced in favor of processing the sugar that was made during lights on.

[Bluey]

Well I feed say 3 times a day and once at night thereabouts and I was starting to get algal
growth on one of the pots.

Each feed at max they would take about 4 to 5 gal ( 5 off 7gal pots) when they were at there thirstiest, so more than 2 gal per day each. From memory a few maxxed out around 2.5 gal/day.

When I had 4 not quite so large plants (harvested about a pound each total) in 13gal pots a 25 gal reservoir would last
about 5 days max at there peak.

I automated it in minutes and adjusted the sprayers to deliver the correct amount. Sprayers would regularly block and flows would slow a tad as the week went on so I'd just give it a bit more on the timer remotely. I wouldnt do it without a drain to waste because of risk of flooding. Manually I didn't bother draining to waste, just used saucers I'd have to suck dry from time to time.

[Rootsruler]

I'm thinking of setting them up on a reservoir/auto irrigate and program in around 8 -12 feed events a day on the digital timer. I'm thinking that it would also be a good idea to give them a deep watering once a week to make sure all the media gets wet.

In veg that would mean they get a feed every 1.5 to 2 hours at lights on. Obviously the feed times will be around a minute or two per event but I'll need to stay on top of the timing and intervals as the water needs change to make sure the volumes are correct.

Bluey - I'm thinking of using the amounts of water I typically use at whatever growth stage the plant is at as a basis to determine the feed event volumes, In five 7 gal pots I was feeding around 5 - 6 gallons in veg and around 6 - 7 in flower every 3 - 4 days. If I run 8 events a day that would mean each event would use around an 1/8 of a gallon or around 480ml per event. Obviously in early veg they'll get less but, I would say after week 3 of veg, this is the volume I tend to see. I may add a few more ML per event to make up for evaporation but I think I'm pretty close.

I'll adjust as I go along but I think this would be a good way of having a threshold to start from.

What do you think?

[Bluey]

I don't measure anything in runoff because I could not get consistent results, especially with pH, so gave up on that approach.

The way I do it is just increasing the frequency dependant upon how much the plant is taking up and pot size. Sure its guess work but I feed them a litre or two to soak the coco then just give a little bit to first sign of run off then stop, if taking up a lot, I'll feed more often but try and avoid runoff for most feeds. I'll only give runoff about once every 4 to 7 days but a good amount, say 20%. At those frequencies you need to watch for algal bloom on top of the coco and its easy to see the slightest color change by just moving your finger through the top ¼" of coco and looking for change. If it starts I'll reduce the frequency if feed by 1 per day. Seems to work.

Last grow plants were so large I gave them all half a gallon in the middle of the dark period also and 3 to 4 times during a 12 hour day depending on their uptake. Minimum feed was a half gallon at a time in 7.6gal pots. They each produced over a pound of great but and about ¾ of a pound of average to poor bud for processing for hash/butter. I hand watered them and that was exhausting but it made me watch them closely and it worked out great.

[Rootsruler]

I think the key to fertigation is the constant presence of nutrient in the rhizo along with being able to keep media saturation levels at a constant where the plants are able to freely do the O² exchanges they need to max the potential of the plant.

The way I understand it is that when we traditionally water our plants, the first few hours is really dedicated to the media equalizing the saturation levels through capillary action while the plant continues to do its thing with what it has within its vascular system. Once the saturation levels reach a certain point, O² exchanges become easier for the root system and performance increases but there is a time lag before the media reaches these levels whereas Fertigation essentially operates constantly at these ideal levels as long as you can keep the saturation levels at a point that allows the plant to maximize its exchanges.

The trick, from what I've observed, is in being able to determine where those levels are. I've seen some measure their runoff to see how much food the plant is taking up and adjust accordingly. Part of those adjustments are light energy and media saturation levels. This is the balancing act part that tends to keep most growers from diving into this type of irrigation strategy but I've seen the results. I'm already taking measurements so a few more to increase my yields exponentially is more than worth it.

[Gingerbeard]

Well, let us see how this goes...

[Bluey]

I use between half and about 80%. They say you can't really overwater a coco grow but you can cause problems if you keep it too wet with algae growing on top or fungus gnats, so if I get a green haze on top of the coco I back things off a bit.

From what I can gather you'd use a bit more in DWC and less in something that resembles soil.

[Gingerbeard]

Dang you all and your making me look up fertigation! I was planning on doing half my usual amount of full dose nutrient solution more frequently, this grow. Keep the coco good and wet. That's sort of fertigation, huh? Maybe quasifertigation? Is fertigation why some of you people get such big plants using half dose nutrients?