1st Coco attempt 1x1m tent: very slow and brown tips

[Mad Flavour]

Hi - this is my 2nd ever grow. I got some great advice on this forum that has seen 4 photo's in organic soil under SF4000 LED through to harvest this week and they look and smell amazing... so now I'm trying perpetual harvest cycle with two tents and started a 1x1m veg tent with coco coir in the start of September 2020... hopefully that I would flip about now as I harvest the flower tent but my progress seems very stunted and slow, with brown tips.
I'm in Australia so the guide I'm following was attractive as it was local products from a DIY warehouse close by I can scoot over to any time to grab items - hence the Nitrosol as nutes. The guide says it's quite adequate for veg for the coco grow I'm trying.

• 1x1m tent
• 100W Samsung Quantam board plus a 400W batwing MH
• Coco with perlite
• 15 ml of Nitrosol to 4 litres of water every couple of days
• Temps stay between 20 C and 30 C
• RH is 65% with a humidifier
• Extraction and internal fans blowing
• Started as clones (from my now flowering plants before they flipped) - OG Kush & THC Bomb
• This is WEEK EIGHT of veg!!

I was trying coco mainly for how much faster / bigger yield it could get so I'm a little confused.
I'm keeping ph at 5.5 to 6
I'm not checking runoff - I only just ordered a PPM meter but have a ph meter, so next feed (maybe tomorrow) I'll check that runoff and report.
Maybe it is overwatering, and nute burn.. so I've left them without any extra watering for 48 hours and maybe another 24 hours until I see that top layer of coco dried.
Thanks for any tips!

 

[PE636]

Were the clones rooted in a smaller container or aeroponic cloner before going in these containers or just straight into these? I see water below the pots, are they elevated above this or sitting in the runoff?

 

[Mad Flavour]

Yes rooted in tiny little things, transferred to these larger pots once I saw roots poking out the bottoms..
Yep you can see run off but the is on the tent floor, and these pots are up on a little glass table. I do mop up the runoff, I just snapped the pic before I did it. I even put the pots up on little bits of foam so the holes at the bottom have clearance for run off!
I'm interested in testing the run off as it's way browner than what went in.. I did a full flush of the coco and primed it with some ph balanced water and calmag..
I've been reading on these forums that I might have my LED too close, I'm trying it way higher as of tonight. (To the roof)

 

[PE636]

Ya could be especially if you are running the 400 as well!

 

[Redcup]

Some suggestions...

Did you buffer your coco? Even if its bagged pre buffered coco you should buffer.

You should water very day, multiple times a day, with fertilizer every time. Coco is essentially a hydro media and should not dry out, you will get root burn. It has great porosity and does not get waterlogged like peat Especially mixed with perlite. Dont water it like its soil. get 20% runoff each event to prevent salt buidup.

Your feed should be around 1000 uS EC.
Your runoff should be around 1200 EC. Your EC meter will help you greatly.
your pH should be around 6.

I dont know the nutrient line you mention, but it seems its organic. You should supplement with a beneficial bacteria innoculant to increase microbial activity. URB or tribus are examples (I dont know whats available to you). In a pinch a good compost tea will help. Its not strictly necessary with synthetics but more necessary with organics.

check that the nutrasol contains all the trace elements.
growing in coco requires a cal mag supplement due to the nature of coir, it immobilizes Ca.

a flush might do some good at this point since you havent been watering enough. flush with your nutrient solution for 100% runoff then resume normal schedule. It seems from your comment you have tried this.

that should help. When you get it going, the performance in coco is fantastic. I have been using it for a few years.
Good luck

 

[Mad Flavour]

Happy to report I have some spurting veg growth in the last week. Here in order is what I think helped

• Raised lights as high as possible
• Reviewed nutrient strength to be much lower and added a drop of calmag
• Checked pH in was 5.5-6, run off after a flush had pH out of just .1 or .2 higher
• Increased air flow in tent

They really pushing hard now and I'm LST pretty aggresively and they are responding well.
I just got a PPM meter and fresh water is about 197 and the current feed is about 370, in and out.

I think if I remind myself of the above points each time I start a veg cycle hopefully I wont have the slow start again... but I think we are off to the races now! Thanks for the tips.

 

[Mad Flavour]

Looking great - all in large fabric pots now, growing fast. Another month of veg then flip.