Screwed up auto grow

[Deezy]

hi all,
small grow of 4 plants for personal use, 1x1m grow space with platinum 450w LED, room at 16-20 degrees c.

growing with flora trio + cal mag as per the advised 12 week coco grow schedule on here.

week 5 and i have seen very slow growth on my autos, they started healthy but im now seeing a rust like marks on the lower leaves as per picture.

done some research and it says calcium deficiency... im giving them calmag everywater at 5ml per ltr, water is ph'd at 6 and run off is 6 i really dont know why this is happening?
I thought it may be nute splash when watering but its definitely spreading... any help much appreciated!
thanks

[dontknownuttin]

Just a guess PH trouble or CalMag problem. Better ask Green75

[Deezy]

Attached the pic as it wouldnt let me add attachments previously, hope you can see it

[dontknownuttin]

Attached the pic as it wouldnt let me add attachments previously, hope you can see it

Nope no photos. Please post a photo and a expert (not me by any means) Will advise

[Deezy]

hope this one views better.. smaller image the last one was massive

[dontknownuttin]

Nope still no photo

[Deezy]

Anyone else? I can see them on all 3 of my devices??
Just upload the image to the server right and click the size you want and the image pops into the post? To be fair ir keeps saying im not authorised still? But i can see them...

[CCisme]

wierd I cant see them either, wonder if you do need to be approved.

[OzBud]

I can't see them. The file size might be too large. If you want try to pm them to me and if it works I'll try reposting them back here for you.

As for calcium problem, I would associate that more with newer growth up higher it can affect lower growth though. Also 5ml per Litre or per gal? 5ml per L is excessive

[dontknownuttin]

Did my photo came through?

[CCisme]

Yes and Lol I always prefer smokable to roses

[OzBud]

yes it sure did

[OzBud]

there's a little camera icon to the left of the reply box at the bottom of this thread, have you tried uploading using that?

[OzBud]

If you're interested and you have Microsoft Excel I have created a GH feed calculator for coco using the GH feed chart. There's instructions for it in the text file.

[NebulaHaze]

I'm sorry you're having trouble with pictures Could you try following the steps in this tutorial to upload, and see if that works for you? There are three different ways to upload pictures to your post, and I'm hoping one of them works better for you! Another idea is you can upload the pictures to Imgur.com for free, and post a link to them from here.

You mentioned you're seeing rust-like marks. Are they happening on the parts of the plant that are getting direct light from the LED? I only ask because some LED grow lights are extremely powerful, and the high light levels can sometimes stress out your leaves even if the temperature is cool in there. It often doesn't happen right away, it's just that leaves that get a lot of light end up dying early.

Regarding the temperature, 16°C is actually pretty cool for cannabis. Cannabis plants grow slower than normal under 21°C, and grow fastest at around 24-25°C. Can you possibly warm the grow space in some way? For example by making it so less heat from the LED gets out, or by adding extra light in there? Even if the cool temperatures are not causing the problem, keeping it a little warmer will likely make them grow faster in general.

How much are you watering at a time, and how often? Do they ever look droopy?

[Deezy]

Ok I tried this another way, let me know if this worked!!

Thank you all for your help so far, yes sorry 5ml per Gallon on the calmag, I upped it due to seeing this problem and diagnosing it as a calcium deficiency but that didn't work, maybe I'm over doing it?
the leaves effected are at the bottom, mainly the first 2 sets of proper leaves, they look like they are fading to yellow and dying, the new growth appears healthy (for now).

The temp is 16-20 due to British weather, I have a heater but when the extractor is running it sucks the heat clean out the tent, the LEDs don't produce much heat either so its tough although its getting warmer so maintaining 20 should be easier as we get closer to summer. I picked lemon autos because the seedbank said they were good down to 10c and fine in cooler climates?

I'm feeding them maybe once every 5 days, this is because the coco doesn't get dry up to the first knuckle for a while.... I have been alternating nute+calmag with Phd water + calmag (only since this issue occurred) usually just nutes and plain PH'd water. they plants aren't droopy at all.

Thanks again,
D

[OzBud]

5ml per gal in coco from seedling until flower is good than 2.5ml per gal during flower.

[Deezy]

Oz, do you calmag with nutes and on just Ph'd water days? Or only with nutes?

Also as autos flower early, do you drop 2.5 as soon as you see buds form?

Thanks man

[OzBud]

I use nutes every day, no plain waterings, no days without watering (except when very young). Only one plain watering I did was the day before I changed from the transition feed to the early bloom feed. I water with plenty of runoff so not really worried about salt buildup despite it being recommended to alternate plain watering with feeding or at least one plain watering per week.

Some people switch to transition or bloom feed as soon as pre flowers appear on an auto, I like to keep going with veg feed for at least another week or so during the stretch so they have plenty of nitrogen to help them grow bigger. Once I see actual budlets start forming I switch over to the transition feed.
I'm at the end of week 7 now, if you look at the gh chart you have I did week 1, 2, 3, 3, 4, 5, skipped week 6 and went to week 7 as the auto wont go the full 12 weeks. might skip another week or two somewhere else as well depending on bud development/ripening. I start at 50% strength and slowly work my way up until I see a tiny bit of nute burn on my leaf tips so I know what the plants can handle and then back off 5%. I got up to 80% strength before I saw the beginning signs of nute burn and have been watering at 75% of the feed chart measurement ever since.

I used 5ml per gal of calmag right from the start until I started the week 5 early bloom mix. By then they should be out of the woods in terms of possible calmag problems in coco from the higher than recommended doses to begin with during their rapid growth (you'll notice the bottle labels are different to the feed chart suggestions for calmag) and then the standard dose should get you through to harvest with no problems although you could probably do one full dose a week if you wanted a bit of extra peace of mind.

Any other questions fire away, i'm more than happy to help.

[Deezy]

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