HELP! My first grow, want it to be a success!

I finally decided to grow a pair… and grow a pair.

There seems to be some absolute grow wizards on here so PLEASE help im very keen to learn! Anything you have to add is greatly appreciated.

Im using;
Seeds: autoflower haze
Medium: canna coco pro, in root nurse fabric pots.
Light: full spectrum led veg/bloom (draws 170w any ideas on height?)
Tent: 1.2m x 1.2m x 2m at 20°c (maybe a bit big?)
My starting water has a EC of 138ųs/cm or 66ppm (i believe this is low?)

Ive bought;
Canna a+b
Canna rhizotonic
Canna cal-mag
Ph / EC testers
(All for when i figure out when they are needed)

Im about 3 weeks in now since they came through the medium. I transplanted them into the bigger pots and gave them some some rhizotonic as a watering method and spray (at cannas recomeded mix) as they were started in plastic cups. The coco was soaking wet with my standard water when i first transplanted them. (how shall i need to water them to ensure good root growth while there small?)

One grew slower and came through with the first set of leaves brown and damaged but has since grown a new set above this…Yet the new leaves do seem very small.

The other grew much taller (so when i repotted it i dug deeper) and it grew its next set of leaves quicker and started going… good i suppose… but now has a yellow colour on the its newest leafs, a yellow unlike any articles i can find an read.
Any ideas?

The bigger one with yellowing leafs;

The smaller one;


The tent/light;


Welcome and looks like you are on your way!

So here’s a couple of pointers:

Put a clear dome over your sprouts as they like high humidity. Seedlings actually derive their moisture out of the air through the first leaves until a taproot develops (about 2 weeks). Water very sparingly as you can damp off the plant and kill it.

Seedlings are stretching a bit: you can bring your light down a bit to help with that.

I would run 24/0 light schedule until planted in their forever home at which point 16/8 is good. (plants need darkness to sort out the previous day’s growth. Salts and sugars are transported around so it’s a good idea to give them a dark period.

Your tap water will be fine.

What meters did you get? Hopefully not one of those ‘3 in 1’ meters as they are generally worthless.


Thankyou @Myfriendis410 , i will make sure i get them domed next time they are seedlings and giving these two threre dark periods.

Luckily not, i nearly bought a 3 in 1 meter but by error recieved just a Ph meter and had to buy a separate EC meter.

Do you have any idea what could be causing the yellowing of my leaves?


They are ready to be fed. They are telling you they are hungry. Go easy at first: 250 ppm or .5 EC for a week and slowly ramp up. Don’t forget cal mag.

BTW: Your tent is enough to do 3 plants at most IMO. But I like high yields.


@HazeyUK seems @Myfriendis410 got ya hooked up. along for the ride to watch your girls grow. Good luck bud!!


Thanks @ggc1962 any experienced eyes on my journal is good news!

Okay so ive gave them a feed,
i only mixed up about 2L of feed using;
drop of cal mag
2ml of canna rhizotonic
2ml canna A
2ml canna B
I then measured my ec (unaware of my issue) and it looked okay…
BUT my ec meter had internal moisture, distorting the LCD screen, ive dried it and now believe to wrong by a whole unit out on my measuring. Not 0.5 EC as @Myfriendis410 recomended but actually 1.5 EC due to reading error.

My larger plant has shown a serious dislike to something, the leaves dropped and went soggy with brown colour…
Here’s some pics;

So i think it may be either;
A problem with the feeds concentrate/feeds EC? Nute burn?
Over watering? I use fabric pots that are always lifted off the floor so drainage should be suitable right? Also I believed you couldn’t over water in coco?
I feel like i have over watered but i have only gave them just over 1 Litre each?

Im thinking this because the larger plant was alot taller than other therefore planted deeper, i think its roots are lower in the pot and they stay more wet… but can you over water in coco?

What have i done/said thats wrong, how can i fix it?
What have i done/said that right? (if anything😂)
Thanks for the help its really appreciated!

Yes! :grinning: It looks like nute burn to me. But be very sparing with water and put a dome back over it. The plant will recover just fine. I think the plant is too small to flush. BUT! If the damage progresses to newer growth you will likely be forced to flush.

And when plants are small it is easy to over water with some coco. If they were mine they’d have a clear dome over them and maybe 2 tablespoons of water per day. It makes sense: the plant is forced to ‘hunt’ for a source of moisture and it does so by pushing roots. Cannabis likes very airy soil and saturating the substrate will cut down on O getting to the roots. Later; when the canopy matches the roots, you will be watering daily.