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First coco grow -> very slow growth

Snypie

Active member
[FONT=&quot]Hy folks,[/FONT]
[FONT=&quot]
[/FONT]
[FONT=&quot]Please help me find out what i am doing wrong.[/FONT]
[FONT=&quot]
[/FONT]
[FONT=&quot]I have 5 indica dominant strains, they are 45 days old from popping out. I germinated on paper towel then i put them in root riot. I transplanted them into 0,5L (1/8 gallon) 100% Plagron coco. I don’t rinsed or precharged the coco (the runoff EC was low). I feed them around 300-400 ppm on 0,5 scale. Last Friday i transplanted them into 2,2 liter (~0,5 gallon) Plagron coco and feed them 500 ppm. PH alwasy 5,8. I always water to 10-20% runoff (the water amount is about 25% of the pot size). I use RO water with BioNova Coco Forte A+B. I use also a root tonic from House and Garden called Roots Excelurator Gold (0,3 ml/liter around 20 ppm).[/FONT]
[FONT=&quot]
[/FONT]
[FONT=&quot]Coco Forte A:[/FONT]
[FONT=&quot]NPK: 8-0-0 + (15 CaO, 3 MgO)[/FONT]
[FONT=&quot]0,003 % Cu
0,066 % Fe
0,016 % Mn
0,009 % Zn[/FONT]
[FONT=&quot]1 Liter = 1,42 kg[/FONT]
[FONT=&quot]
[/FONT]
[FONT=&quot]Coco Forte B:[/FONT]
[FONT=&quot]NPK: 0-6-12[/FONT]
[FONT=&quot]1 Liter = 1,19 kg[/FONT]
[FONT=&quot]
[/FONT]
[FONT=&quot]My setup:[/FONT]
[FONT=&quot]1m x 1m x 1,8m tent[/FONT]
[FONT=&quot]250W CMH with Hydrofarm Radiant air cooled hood[/FONT]
[FONT=&quot]24-25 Celsius daytime[/FONT]
[FONT=&quot]21-22 Celsius nighttime[/FONT]
[FONT=&quot]75-80% RH daytime[/FONT]
[FONT=&quot]65-70% RH nighttime[/FONT]
[FONT=&quot]
[/FONT]
[FONT=&quot]I tried the wet-dry cycle to help roots fill out the pot, so i water every 2-3 days, when the weight of the pot is the same when i filled the pot out of the bag. When I transplant last Friday the pots was full of roots, but they were thin. I can’t decide this is overwatering (lack of oxygen) / underwatering or over/under fertilising. In my opinion this is not overfeeding because the runoff EC is the same as the inlet EC. One thing i see from last transplant, my runoff PH is very low, 5,2-5,3.(In the smaller pot the runoff PH was always 5,9-6,1) But before that the growing was also very slow and the plant was always pale green. I used to spray them with Bio Nova Spray mix (which is kelp based product) and this is always helped. So i am thinking it is Mg def (or calmag).[/FONT]
[FONT=&quot]
[/FONT]
[FONT=&quot]What do you think what am i doing wrong?[/FONT]
[FONT=&quot]
[/FONT]
[FONT=&quot]In my opinion possible cases:[/FONT]

  • [FONT=&quot]watering schedule or freqvency or amount[/FONT]
  • [FONT=&quot]nutritient problem[/FONT]
  • [FONT=&quot]Calmag problem (maybe mix RO with tap water?)[/FONT]
[FONT=&quot] [/FONT]
[FONT=&quot]My goal is to transplant them into 1 gallon fabric pot, and switch to drip irrigation (i made a system ala PICO) and feed multiple times a day. But now i am far away from this.[/FONT]
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[FONT=&quot] [/FONT]
 

Mikell

Dipshit Know-Nothing
ICMag Donor
Veteran
Interesting. Some looks like nutrient burn, but it is hard to see. Your run off pH leans toward this but as you say the EC is similar to feed. Have you run this strain before? Can you take a picture under natural lighting?

I would contact the nutrient manufacturer about using RO with their line.
 

Snypie

Active member
I took new pictures:



Today i buyed a fresh PH and EC calibration solutions and seems to be my ph pen was off by 0.2-0.3 points and the EC meter was off by 0.1-0.2 EC. So this will be overfeeding and this is why my PH is low.
I contacted the nutrient manufacturer last year and they gave me doubtful answer. They said that i can use RO or tap water. It will work all of them. But here a grower said that my nutes made for RO water because of the high Calcium content. But this is not working for me. I don't tried it with tap, because it has 350 ppm.
Today evening i will flush them. I will make a basic water with tap+RO till i reach 100 ppm and then nutes till 400-450 ppm.
 

Lester Beans

Frequent Flyer
Veteran
If you are in coco and only watering every two to three days that is your problem.

Try watering 3 times a day, bumping up your feed, and keeping your pH around 6.

400-500 ppm is not enough for 45 day old plants.

Letting coco dry out is the kiss of death. Flush your coco really well then mix a new batch of nutes. Water three times a day aiming for 20% runoff each watering. Best to go drip to waste..
 

Snypie

Active member
Thank you Lester. I have read that thread, that inspired me to try coco and build a drip system. I let the coco dry out because transplant. I will try to water every day.

[FONT=Arial, Helvetica, sans-serif]"400-500 ppm is not enough for 45 day old plants." OK, but they are ~ 5-6 inch height and my soil plant look like this at 25 days. How many ppm is enough for this plant?

What do you think my nuts are for RO?
[/FONT]
 

Lester Beans

Frequent Flyer
Veteran
With RO water I would start by adding Cal Mag up to 200 ppm then other additives, topping off with base nutrient to a total of 600ppm.
 
Depending on the size of the plant you don't need to water 3 times a day.
I hand feed coco in veg and when the plants take root into the pot i water them once a day with a quart of water (they are in 3 gal pots). You must keep coco moist so the salts you are using do not dry up. It was explained to me like a glass of water filled with table salt. As long as the glass has water in it the salt is separated. Once all the water evaporates the salt becomes coagulated.
Also keep a eye on the run off EC/PPM and pH. Make sure to adjust. For example if your run off is getting too high try a day of just CalMag.

Happy Growing
 

Snypie

Active member
I made the flush with tap water and the PH sabilized at 6.0-6.2 for 3-4 days. Then they go down. I watered them 2 times a day with tap water (i don't have calmag, so i used tap water with 260 ppm which is almost Ca + i added epsom salt 0.1 gramm/liter ~ 50 ppm) + nutes till 600. The runoff ppm rises by 20-30 ppm every watering and the PH is lowering. Today the ppm was 350-400 and the PH 5.8-6.1. I found that the smaller plant's PH is decreasing.
The other plant are growing.

When is my runoff ppm getting high? For example if i feed with 600 ppm and the runoff ppm is increasing what i decribed is this OK? Why the PH is lowering? It is salt buildup or overwatering or just not eating enough?

I am going to order some CalMag. It will arrive in 1 week.
 
Last edited:

ibreza

New member
Hey snypie,

Don't be discouraged, I'm sure with a few changes everything will work fine. some thoughts in no particular order:

* It's hard to see but it seems there aren't any roots at the bottom of your container. don't water multiple times per day, this is bad advice. multiple feeds per day is advised when your plants are rootbound as a mean to increase dissolved oxygen in the substrate.
Right now they are far from rootbound, so just feed them when the surface starts drying and you'll be good.
* Do you have an analysis for your tap water? should be easy to get from your provider. Most 2 parts coco nutes are made for tap water, not RO. tap water brings some carbonates stabilizing ph (preventing acidification), some calcium and magnesium.
* To use calmag with RO when your tap water could just be as good seems like a lot of efforts for nothing.
* If you could take pictures of damaged leaves outside your tent, it would be easier to diagnose. To me it seems like an advanced magnesium deficiency: interveinal yellowing of older leaves and really damaged leaves drying. You can add 0,3gram/liter of epsom salt (heptahydrate) to every feed which amount to 30ppm of mg
* offtopic but measure temperature at the canopy and lower your light until you're around 27C. 250w is not much and if your light is not on your plant, you're not going to see rapid growth whatever else you do. also I don't see a fan in your tent, you want a fan on your plant 24/7 to strengthen branches, prevent molding in flowering, and cool down the canopy.
* don't transplant your plants until they are rootbound, meaning you need to water every day or the coco get completely dry and it should look like that https://www.icmag.com/ic/picture.php?albumid=70467&pictureid=1710272
* don't go higher than 0.8EC with no runoff. once your plants are back on track you can reassess if they need more.

post your tap water analysis and keep us updated :)
 

Snypie

Active member
Hey Ibreza,

Yeah, i don't multifeed a few days ago. I went back to watering when the pots are light and the top of the coco change colour. I put a heated propagator tray under the plants which is helping them in the overwatered cycle. I don't have an analysis for my tap water, but i can see some details on the water supply webpage:
Free active chlorine: 0.15 mg/l
Chlorine: 27 mg/l
Iron: 27 microgram/l
Manganese: 5 microgram/l
Nitrate: 11 mg/l
Nitrite: <0,03 mg/l
Ammonium: <0,05 mg/l
Total hardness: 163 mg/l CaO
EC: 0,549
PH: 7,4
No data for the Magnesium.

But yesterday i ordered some calmag, it will arrive within 2 weeks, because i must to wait for something that i ordered too.

I have an oscillating fan, but it can't see in the picture. It is below the hood. It is an oscillating fan 20 cm in diameter and 20W. It is running when the lights on. I have an 280 m3/h extractor, which is running always and half speed.

The bottom of the hood is ~ 25-30 cm above the plants. So the bulb is ~ 35-40 cm. I will lowering it. In flowering i will use 400W HPS (Philips GreenPower).
In veg i always used this 250W CMH, although i am thinking one 400W MH would be better.

I will take fresh pictures of the plant, of the roots and the equipment i have when i arrive home. In 10 hours :)
 

PoweredByLove

Most Loved
have you tried taking one out of the pot and examining the roots? i'm willing to bet the roots are all on the outside of the pot because the inside middle is too wet. also what are your temp? could be too cold. but im' willing to bet you're just watering too often.
 

Snypie

Active member
I took a lot of pictures. One with flash and one without.

Today is day 60.

PoweredByLove: Yes, i look at the roots very often. I took pictures of the lesser one plant. My daytime temp is 25-26 Celsius, and the night temp is 22-23.
I have answered my own question. Why is my PH so low? Because I was watering too often. Now i watered the biggest two after 2 days (the pot was light and the top of the coco has changed the colour) and the PH was on spot. 6.1-6.2

 

ibreza

New member
nice to hear you have solved ph and overwatering problems.
that is textbook magnesium deficiency in advanced stage. feed 0.3g/l epsom salt every watering and your plant should feel a lot better a week from now.

Your water is fine, you don't need ro or calmag. I assume hardness is in CaCO3 and not CaO. It would be nice to have a more detailed analysis but chances are most of that hardness are calcium and magnesium carbonates. Thoses carbonates will be dissolved by lowering your ph with a strong acid (nitric/phosphoric/sulfuric), making Ca and Mg available to your plants => no need for calmag.
 

Snypie

Active member
That's fine, thank you very much!!!
I will update this thread and i would be happy that you will continue to keep track with me :)
 

PoweredByLove

Most Loved
those leaves arent showing deficiencies. they're showing overwatering and root damage. dry it out man it's only gonna escalate.

picture.php


picture.php

over watered bad roots


picture.php


picture.php

better watered better roots.

both plants were like 4-6 weeks from seed. not 100% sure on exact days. but yours are twice as old and in bigger pots should have more developed roots.:tiphat:
 
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