Problem with plants in coco

[KennyKen]

Hi, I'm wondering if any body is able to help with a problem I've been having with this run.

For the first 2 or 3 weeks after the seeds popped through, I had a few things going on so I couldn't really give it my full attention. This meant that they didn't get as regular feeds as I'd of liked so they did dry out a couple of times - and they were over watered twice to the point of droopy twisted leaves. After the second time of over watering, I let the pots dry out quiet a bit before watering again and since then I've been on top of the watering. However, even though they're getting watered regularly, the leaves are still curling under with dry, crispy tips. A lot of the leaves that aren't curling under are showing loght coloured tips and edges and some of them are showing copper/orange marks.


Environment:

Day temp 27c
Night temp 21c
Humidity 50 - 60%
Pots on trays, on heat mats with probe in the coco. Temp set at min 18c
2 oscilating fans for air movement - the leafs on the plants are hardly moving when the fan oscillates past.
2x 650w LEDS set to 450w and 32" above canopy
6" extraction extracting to outside the house
Passive intake coming from in the room where the tent is and from outside through an intake fan which is switched off.

Feeding

Plants in fabric pots, in coco with home made irrigation system. They were getting 1.4ec canna a&b ph'd to 5.8 which raises to about 6.1 over a few days in the res. My base ec is zero so I start by raising that to 0.4ec using calmag before I mix in my a&b. I saw signs of what I thought was nute burn (light coloured tips) so I watered them once with a weak 0.7ec mix until about 50% run off and have been using 1ec mix for the last week to try and fix what I thought was nute burn. I don't think it's made much difference tbh because the new growth is still coming through with light coloured tips.
The plants are about 8 weeks old now so they're watered 3 times a day until run off. 2 hours after lights on, 2 hours before lights off and once in between.

Things I've tried:
Reduced the temp of my roots from 20c to 18c
Flushed them with a weak nutrient mix and reduced the solution down from 1.4ec to 1ec
Raised the height of my lights from 26" to 32"
Reduced the day time temp in the tent from 28c to 27c
Turned on my dehumidifier and set it so my tent max humidity reduced from 70% to 60%

If anyone has any idea what this is or how I can fix it, I'd be happy to hear from you! I'm starting to think that it could be a problem with the roots due to my poor watering practices at the start but I'm not sure how to check that without taking one out of the pot and physically looking...

 

 

 

Leaf tips curling down

 

 

I'm not sure if the light coloured leaves are because I've been feeding 1ec nutes or something else...

 

 

 

Some leafs are a bit pale in patches. You can also see the light tips on the newer growth in this one

 

 

Burnt looking tips and edges

 

 

Burnt looking tips amd edges

 

 

I'm hoping someone will be able to help so I can sort it before flipping in to flower! 

 

 
Thanks
Kenny Ken

[GSZZ]

No mention of run off EC unless I missed it - how are you determining when to add irrigation events?

 

You can see you've cut loads of plant away as well, with a big root system supporting what previously was, I imagine its probably sitting soggy now as transpirational load is lower than what it grew for.

Edited January 29 by GSZZ

[Larry Badgeley]

2x 650w LEDS set to 450w and 32" above canopy

 

900w LED in total or 450w? If it's the former, I would dim them down. That sounds a lot of light. I have never used Coco so @GSZZ might be more accurate

[Herbal Kint]

Think its due over watering but cant say for sure,i mean just look top coco.

 

Didnt find it a problem in coco,they get better once pot is rooted hopfully.

[mikeydoughnut]

Nice spot @Herbal Kint looks almost mossy. Cold n damp? 
 

Root temp is way too cold imo. I love got my heatmat set to 24 with the pots sat on cooling racks

 

Measure run off to find out what you need to do rather than guessing. Broken record recently but it’s solid data. That’s something you CAN get right and cross it off the list. 

[Danny killerZ]

Is this grow in a nice warm household? The transpiration rate is maybe out of sync due to low temps for LED .  Definetly need a halo of warmth constantly for LED grows - Northern hemispheric air is chilly and full of vapour in the winter. Heat mats and extract the humidity at a steady pace will get them back on the road. 

[Herbal Kint]

My saucer that i left a side after watering i forget to empty it looks like top of his coco,i bet if he was using hps it would dry out faster and that wouldnt happen. Maybe peek temps a bit so it drys out faster?

[KC]

I'd have said over watering too. Also pots look too big for that sized plant. How long were they in their finals for?

 

 

@mikeydoughnut On a seperate note, how come you put your pots on cooling racks mate? I just have a tray sat on my heat mats and a saucer under the pot. I imagine you could turn your thermostat down if there was no gap, save some £££. Saying that I set my mat to 24c in flower anyway.

 

Edited January 29 by KC
typo

[mikeydoughnut]

I do use trays from time to time @KCbut tray lips can restrict they lay out somewhat. When yer riding close to the wind like I am you need all the space available. In the veg tent I take them out, water over a trough and once I’m done I just  let them drip through the rack back in’t tent, although I never put them back sopping. I’ll always use trays once into flower to catch run off though.

[KennyKen]

Thank you for so many replies, I've read and responded to each one individually. It seems the general concensus is that I'm over watering. Is the best way to fix this to water less or to raise the temp?

 

If I raise the temp, I can do that by either turning the lights up to a higher setting, turning the stat on my oil rad so it comes on during lights on along side the LEDs, or I could put my dehumidifier in the tent and see if that helps raise the temperature. 

 

If I'm watering less, I'm going to have to hand water for a while so I can be sure that only the ones that are dry are getting watered. They're all on the same feed line at the moment so its water all or water none. I don't mind hand watering them, obviously I just want to fix the problem and not sure the best way to go about it! 

Hi @GSZZ thank you for your reply. I hadn't checked the run off so I've just watered them and took a fresh reading which is 0.1ec and pH6.8/6.9. I'm not sure what that means. Is the ph supposed to rise like that? I've attached a couple more pictures from earlier in their life and you can see that my poor watering practices have caused some misshapen leafs. You can see that some of the plants are already clawing. I'm sure that the accident I had with the branch, which caused her to lose an arm isn't helping however I'm having the same problem with other plants which haven't had an amputation so it seems like there is something else to it. I hope your right with the over watering thing. How will I know if its caused any kind of root rot or anything?

Hi @Larry Badgeley thank you for your reply. I've got 2x lights both switched to 450w so 900w in total. My tent is 1.5m x 3m. In the past I'd usually turn the lights up again to 525w or 600w each light for flower!

Hi @Herbal Kint thank you for your reply. When I transplanted them in to these 12l pots, I watered them and then left them for a day and the pots felt light so I watered them again. The next day they were still about 50% heavy so I left them and did them the next day. Since then, they had dried out quiet a bit within a day so I started watering them daily. I didnt check all the pots tho, I only checked one pot and then decided to water all the plants because that one pot was dry. That one plant seems to be doing ok atm, I just have 3 that are pretty bad. Maybe they hadn't rooted in before I started the daily watering..? They've been in these 12l pots for about 2 or 3 weeks now.

Hi @mikeydoughnut thank you for your message. I did have my heat mats set to keep the roots at 20c with the probe buried deep in the coco. One night I went to bed and left my spare hygrometer on the tray next to my plant. When I checked the reading the next day, it had peaked at 37c and stayed around there for almost an hour before coming back down. I was worried that I was cooking my roots so I lowered the temp down to 18c so the heat mat came on less. What are your thoughts in that? Should I turn that stat back up to 20c+ and not wory about how hot its getting on top of the trays?

Hi @Danny killerZ thank you for your message. This is inside a warm house but the radiator in the room where the tent is, is turned off to help keep the temps down, which is the problem I usually have. Maybe I should turn the rad back on in that room? I do have a small oil rad that's connected to a thermostat to keep the temps up during lights off. The coldest it gets during lights off is 20c. Maybe I should set it so that during lights on, it runs alongside my LED's to keep the temps up during lights on?

Hi @KC thank you for your message. I think the size of the plant is deceiving with this one because I chopped one of her arms off! The stems on all of the plants are thicker than a clipper so they are pretty chunky tbh. I'll get a pic of one of the other ones in a bit and upload it so you can see how big they are. They were in the 1l pots for about 2 weeks then the 4l pots for about the same. They've been in these 12l pots now for about 3 weeks now.

 

 

A couple of pictures from earlier in the plants life before I topped them.

 

 

 

Thanks again for all your help.

 

Kenny Ken

 

Edited January 29 by KennyKen

[Herbal Kint]

Your figured out problem yourself, they didnt root out , you start watering daily. I go from 0.2L to 1L 3L 6.5L. Takes 2 weeks per pot up more or less,you say they been 3 weeks in 12L ,they should have root it out unless they were cloged up all time?

[KennyKen]

4 hours ago, Herbal Kint said:

Takes 2 weeks per pot up more or less

 

Thank you for the advice @Herbal Kint I went from jiffies to 1l pots after about 2 days, then 1l pots to 4l pots after about 2 weeks and then 4l pots to 12l pots after about another 2 weeks. Maybe I should do 8l before 12l..? It hasn't been a problem in the past but maybe with the room/root temps being low, they've taken less water and so I've ended up over doing it?

 

I've been watering with this 1ec solution for about a week now and changed my watering to once a day about 3 or 4 days ago. Last night I raised my root temps to 22c as recomended by @mikeydoughnut. I was going to go for 24c but when i came to adjust it before lights off, it was on 25c already and I was worried about cooking the roots! I also raised my lights off temp from 21c to 22c and tried to raise my lights on temp by adjusting my fan controller from 27c to 28c as recomended by @Danny killerZ. The problem is, the temp hasn't really gone up and is still sitting around 26/27c. I'm not sure what the best way to rise the temp is. Should I turn my lights up or run my oil rad during the day? About an hour ago I turned my oil rad on to see if that improves things. It's expensive to run a 1200w oil rad 247 though!

 

The good news is that they're starting to look a bit better now, even the 3 dodgy looking ones. The new growth from the last few days is looking perky and not as droopy and the tips don't look burnt. Hopefully they stay like that and don't start showing burnt tips as the leafs mature!

 

I'm going to mix some nutes tomorrow and up the ec because they look hungry and see how they react to that.

 

Thanks again to everyone for helping

 

Kenny Ken

 

 

[yan]

6 minutes ago, KennyKen said:

I'm not sure what the best way to rise the temp is.

I’ve read here that some people extract from the bottom of the tent and intake at the top when growing with LED in winter. It might give you an extra degree for free if it’s possible with your setup and you’re not doing it that way already. 
I reckon the increase in minimum temp you’ve given them already is decent though. 22-24 minimum sounds better than 18. 

[KennyKen]

10 minutes ago, yan said:

I’ve read here that some people extract from the bottom of the tent and intake at the top when growing with LED in winter. 

 

Thank you for the great advice @yan, I used to do extract from the bottom but my fan is pretty long and it took up a lot of space. I left my fan on ratchets though so I have the option of lowering it again. I might try it even if it's just until the plants start to take up the full tent 

 

Kenny Ken

[Hazeytones]

The length of the fan shouldn't make a difference, stand the whole lot upright so filter on the floor fan attached then ducting to wherever you want and your only taking up the diameter of the end of the filter.

 

I don't get why people lay the fan and filter on the floor your just blocking the filter and taking up far more floor space than necessary.