Red Stems on White Widow, Biotabs and Autopot

[Bodhisativa]

Hey AFN

I'm on my second ever grow and have run into something which I'm not sure about, three of the four plants have developed red stems.

The grow set up is:

Converted space in a cupboard measuring 90cm wide, 60cm deep and 150cm high
Light is a 400w Mars II
Carbon filter and exhaust fan, cupboard has negative pressure
Four plants in two easy2grow autopot trays, the pots themselves are 8.5l
Soil is Biobizz and perlite with a layer of clay pebbles at the bottom of the pots
Nutrients are 1 Biotab in each pot, and all the other soil bacteria stuff which comes with the Biotabs starter kit.
Plain water in the reservoir with added calmag
The plants are - 2 x DP Auto White Widow, 1 DP Auto Blackberry Kush, 1 Barney's Farm Blue Mammoth. WW are at day 43, BK 28 and Blue Mammoth day 25.
Temp is 26 Celsius, RH started out 30% and has risen to 55% as the plants have grown

Both of the WW have developed red stems, and the BK seems to be as well. I grew two BK on my first grow and whilst they were like different plants - one had green bud, the other was deep purple/almost black - neither got red stems, I was using AN nutrients in airpots so it was a different set up. From what I've read it could be a phosphorus deficiency but the leaves seems fine. Any ideas?

 

[Joe383]

Your plant looks a little nitrogen toxic which could be causing the problem. I had the same issue with my last purple kush I just harvested. I let the issue go instead of dealing with it at the beginning of the grow though and it got super bad. I don't think your plant is going to get like mine though. I had it in 10 gallons of soil and the soil was extremely high in nitrogen. I would do a light flush, give the plant a few days maybe a week to use up the extra nutrients it has stored up and feed some bloom nutrients + a little mag like Epsom salt or cal/mag supplement if your bloom dose not already provide it. When you flush you might see a slight mag deficiency a few days later but I would not give it tell your ready to feed bloom.

 

[Bodhisativa]

Thanks, I guess this is the problem with using a slow release fertilizer - maybe I need to dig around in the soil and pull out whatever's left of the Biotab before flushing. My first grow without Biotabs went without problems, but getting water to where the plants are turned into a full time job so i thought the autopot/Biotab solution might make it easier. Serves me right for being lazy I guess! I think that a single Biotab for an 8.5l pot is too much, anyone else thinking of doing this might want to try with half a tab with a pot of that size...

 

[Tricycleofdoom]

I recently had my stems turn dark red, on top side, a week flowering. Turned out to be just a variety (phenom? ) for Jack Herer auto. During last 2 weeks before harvest, the upper buds and leaves turned a beautiful crimson purple. You can see the red stems between the leaves...

 

[Bodhisativa]

I do like a bit of color, so maybe I shouldn't complain! The plants seem to be developing normally apart from the red stems (and the red stems are only happening on the top of the plant, the lower ones are still green), so I'm going to leave as is and see what happens. I'll update here in a couple of weeks.

 

[jayc93]

I have used a biotab in a regular 7.5ltr pot with a cherry bomb auto had some nitrogen issues late flowering too i have started feeding biobloom and topmax now she's on day 53 I think today check out my grow below yours looks great btw!!

 

[Joe383]

I recently had my stems turn dark red, on top side, a week flowering. Turned out to be just a variety (phenom? ) for Jack Herer auto. During last 2 weeks before harvest, the upper buds and leaves turned a beautiful crimson purple. You can see the red stems between the leaves...

Looks like low P. Good looking plant though.

 

[Dion]

i grew some jack photos a while back and about half of them had purple stems

anymore info on the tabs?
Im thinking of those or supermix from plegron for next run