Seedling not growing :/ help please

[DarthMaul]

Hi everyone,

I'm having issues with 3 of my seedlings.
This is my 5th grow and I never encountered something like this.

Only feed them 2ml voodoo juice with plain tap water.
It's been already 16 days since they broke the soil and they barley grew....


My setup:

400W HPS 2x fans / 2 intake / 1 exhaust
Coco Perlite mix
Autopot system
3x AutoMazar from Dutch Passion seeds were frozen for around 1 year

Measurements:

20-28 degrees
RH 30-40
Checked PH 6.0 when testing water from the bottom of the pot

Issue:

Yellow, leave's browning and stunt growth please see pictures below.
I tried to spray Revive on them once per day but it didn't help so far.

Thanks!

 

[namvet25]

Could be a bad batch of coco,and it looks like you have a little to much perlite also.I don't recommend spraying anything on seedlings that small.I believe the ph in coco should be under 6 but I will see if i can find out for sure.

 

[Gatorbackbob]

I agree with namvet, it may be bad coco, I don't know much about coco, but some bags aren't ph stabilized and require a heavy rinsing/ washing before using

 

[Eekman]

I don't know, but water should be targeted to a PH of 5.8. You should give them some feed at about 1/4 strength. And some Root stimulating additive. Think about cal mag at the third set of leaves.

 

[Duggy]

Hi @DarthMaul
They look a little stunted at this point.
Coco contains no nutrients so feeding is needed from the outset, usually at quarter strength to start. I normally wet the coco with quarter strength nutes and calmag prior to planting too...
If you have more seeds to start again it might be beneficial.
If you are continuing I would feed them at quarter strength with some calmag if you have it, pH feed to 5.8 and feed until run off.

 

[blue]

I don't know, but water should be targeted to a PH of 5.8. You should give them some feed at about 1/4 strength. And some Root stimulating additive. Think about cal mag at the third set of leaves.

I fully agree with this

I'd start this one over (as you really want day 20 for the leaves to have reached the side of the pot), and chalk it down to bad luck and some iffy coco.
If you water every time at 5.8ph, and don't let the get very dry ... you can be pretty confident you'll stay in (nute uptake) range for the whole grow.

The run off method of testing isn't great for coco (according to canna), so best just to measure every time you feed to be sure!

Hope this helps

Blue ^_^

edit: ... and what duggy said (while i was typing this) ! ^_^

 

[budelee]

All great advice guys.. i grow 99% of mine in coco and there are some variables( as always) that can cause issues like this. I didnt see any info about what type coco( brick or bag).. was it rinsed or precharged, is it ph buffered..STOP the spray until we get you sorted or you start another batch... are you overwatering which could cause stunting, coco has great aeration capabilities but should not be kept saturated( roots cant breath and this could cause a shallow root system which will result in a smaller plant) especially with babies.. are you pH ing the feed going in? Nutes could be locked( this one is a long shot but still possible).. RH seems a bit low but not horrible... not all plants at 20 days will be the same size and mine aallwayyys move slow for the first 0-20 days... give us a bit more info and we will get you on the right path

 

[Waira]

.... day 16, no nutes at all? For sure this is part of the problem; notice how the cotyledons are wiped out already?....No Ca-Mg either? Bad news in coco, mate, have you read up on coco's odd CEC properties? it's a huge Ca hog, Mg to a lesser degree, so unless you have coco dedicated nutes, Ca-Mg is necessary no matter what, even water alone is bad news for the cation buffering balance,.. coco is more like hydro' than true soil/soilles in many aspects, and if you treat coco like other soilless mixes (Promix, etc.), or true soil, problems are certain to happen,... Also, badly prep'ed coco (iffy brands, bad batches) may have too much Na in it, and K too, but Na is toxic at low levels.... like Blue said, run-off is generally not a good measure of actual in-pot pH, but because this is so early on, with no other inputs, it's probably fairly close, and is OK,... all in all, they stunting is severe enough at this late date to consider a total reboot,.. sexing is a week away at best, and after that, vertical growth slow a great deal,...

 

[DarthMaul]

Hi @DarthMaul
They look a little stunted at this point.
Coco contains no nutrients so feeding is needed from the outset, usually at quarter strength to start. I normally wet the coco with quarter strength nutes and calmag prior to planting too...
If you have more seeds to start again it might be beneficial.
If you are continuing I would feed them at quarter strength with some calmag if you have it, pH feed to 5.8 and feed until run off.

I fully agree with this

I'd start this one over (as you really want day 20 for the leaves to have reached the side of the pot), and chalk it down to bad luck and some iffy coco.
If you water every time at 5.8ph, and don't let the get very dry ... you can be pretty confident you'll stay in (nute uptake) range for the whole grow.

The run off method of testing isn't great for coco (according to canna), so best just to measure every time you feed to be sure!

Hope this helps

Blue ^_^

edit: ... and what duggy said (while i was typing this) ! ^_^

.... day 16, no nutes at all? For sure this is part of the problem; notice how the cotyledons are wiped out already?....No Ca-Mg either? Bad news in coco, mate, have you read up on coco's odd CEC properties? it's a huge Ca hog, Mg to a lesser degree, so unless you have coco dedicated nutes, Ca-Mg is necessary no matter what, even water alone is bad news for the cation buffering balance,.. coco is more like hydro' than true soil/soilles in many aspects, and if you treat coco like other soilless mixes (Promix, etc.), or true soil, problems are certain to happen,... Also, badly prep'ed coco (iffy brands, bad batches) may have too much Na in it, and K too, but Na is toxic at low levels.... like Blue said, run-off is generally not a good measure of actual in-pot pH, but because this is so early on, with no other inputs, it's probably fairly close, and is OK,... all in all, they stunting is severe enough at this late date to consider a total reboot,.. sexing is a week away at best, and after that, vertical growth slow a great deal,...

Thanks for the feedback everyone it really helped me understand the problem. I did a mistake to treat coco like soil and I payed the price for it. I usually grew coco/soil mix wanted to go full coco this grow.
Seeing how easy it is to fail with coco I'm considering going back to soil/coco mix. I have only 3 options in my country 1. coco/soil 2. soil with perlite 3. coco with perlite and ph adjustment. I'm going to restart the grow in a few days.
Do you think I should give coco another try or go back to what i grew before? I'm afraid to fail again lol

Both the coco/soil and soil gave me nice yields before so I don't think the soil/coco is the issue :/ Can I reuse the Coco if i do decide to try again ? They barley grew so no roots there.

All great advice guys.. i grow 99% of mine in coco and there are some variables( as always) that can cause issues like this. I didnt see any info about what type coco( brick or bag).. was it rinsed or precharged, is it ph buffered..STOP the spray until we get you sorted or you start another batch... are you overwatering which could cause stunting, coco has great aeration capabilities but should not be kept saturated( roots cant breath and this could cause a shallow root system which will result in a smaller plant) especially with babies.. are you pH ing the feed going in? Nutes could be locked( this one is a long shot but still possible).. RH seems a bit low but not horrible... not all plants at 20 days will be the same size and mine aallwayyys move slow for the first 0-20 days... give us a bit more info and we will get you on the right path

Thanks for the tips man - soil/coco is limited in my country don't have much of a choice. I did PH the water but only to 6.5 :/ I want to restart my grow but afraid now to continue with coco. Since you are a coco grower do you think I should try it one more time? Can I reuse the coco for the new grew since they barley grew? What is your opinion on soil/coco mix?

 

[Waira]

hybrid custom mixes are a gamble mate, depending a lot on the ratio of coco:soil,.. always, coco will hog Ca,... But true, many true soil mixes have coco in them, it;'s the other amendments that make the big differences,... Check out the coco section here to learn more, and Canna Coco has great info at their site,.. it'll take some digging around, but it's there,... If you've had good success with mixes, stay with it, just be mindful of what coco is and isn't bringing to the table,... otherwise, treat coco more like hydro, because that's a more apt analogy,... frequent, lower ppm feeding, lots of run-off to avoid salt build-up (like about 20% run-off in drain-to-waste),.. upside, is you can use smaller pots and still grow monsters! I'm not a coco grower, so look up Budelee or Arty-Zan too,.... just make sure to use quality brands of coco an soil, especially coco,.. bad shit is still loaded with Na and too much K, native cations that need serious aging and rinsing/ cation buffering to purge and make safe for use,.. this is the makers job, not yours,...