Mephisto Genetics in coco | First time grow

[lessonslearned]

Hi everybody,

I'm growing 25 Sour Cracks and 12 Chemdogging - AF SOG style. I'm experiencing some problems with Sour Crack babies.
Coco/Vermiculite/Perlite - 80/10/10. I've used this coco (Superior Light Mix) and added a bit of vermiculite and perlite. There is guano added to coco, so it is claimed that it isn't required to add any nutes first two weeks.

Pot sizes: 6L,5L.
Feeding: 100-150ml of 6.0 ph water/ each plant every other day. Yesterday added 2ml/10L of Bio Roots by GHE and 1ml/L of Ionic CalMag Pro by Growth Technologies.
Temp: ~28-30 C during day, and 21-22 C during nigh.
Relative Humidity: ~25-30% during day (I know it's very low, can't help it), ~35-40% during night.
Light: 20/4 - 2 DIY LEDs set on 500 true watts (planing to add HID lamp on flower).
Vent - Soler&Palau Silent 500/160.

Here is the full tent pictures:
View media item 17801View media item 17799
The plants I'd like to ask you help with:

2 Spades:
View media item 17800View media item 17798Sour Crack | Day 14. I guess it is going to die. One leaf is curled inside, and another one is deformed. Not to mention the tip burns.

King Spades:
View media item 17797Sour Crack | Day 14. I guess it is going to die. Overall a weak plant.

Ace Spades:
View media item 17796Sour Crack | Day 14. The had been stunned from the very beginning. It's growing, but slowly. Can I help her?

4 & 8 Clubs:
View media item 17795View media item 17785View media item 17789View media item 17790Sour Crack | Day 14 - Yellowish leafs. CalMag deficiency?

10 Clubs:
View media item 17786Sour Crack | Day 14 - Tip burn on the leaf edges. What to do?

7 Clubs:
View media item 17782View media item 17784
Sour Crack | Day 14 - One of the biggest plants of the garden. Tip burn on the leaf edges. How can I help her?

7 Spades:
View media item 17783Sour Crack | Day 14 - Weak plant overall. Would like to help her to get a good pace.

Sorry for lots of "patients" to be diagnosed. My box is 90 x 200, it's kinda limited space, so if I lose couple of them - that's okay. But If I can help them - I'd love to do it with your help.

Thanks in advance!

 

[AutoWonders]

Well god damn, your ladies are smart enough to play cards? Amazing.
Nitrogen can attack young plants quite often. One plant looks to have nute burn. It's a good move to start nutes at 1/4 the published amount and see how things progress from there.
I posted earlier about how well Peruvian seabird guano has worked for nitrogen deficiency. I let one plant get completely engulfed with that deficiency (one plant earlier as well) and the guano brought it back quite well. Happy harvest.

 

[lessonslearned]

Well god damn, your ladies are smart enough to play cards? Amazing.
Nitrogen can attack young plants quite often. One plant looks to have nute burn. It's a good move to start nutes at 1/4 the published amount and see how things progress from there.
I posted earlier about how well Peruvian seabird guano has worked for nitrogen deficiency. I let one plant get completely engulfed with that deficiency (one plant earlier as well) and the guano brought it back quite well. Happy harvest.

Thanks for a reply, AutoWonders!
The cards is an amazing way to differentiate the plants given their number. Makes logging much easier.
The thing is, I don't believe there can be a nute burn. Which plant you're referring to? I fed them only once with CalMag and Bio Roots. The coco I used contained guano, and it is advertised that no need to add nutes during the first 2 weeks.

Spoiler: Here is description of the product

Pure Superior Light Mix is a 50 litre bag (±5%) of medium structure cocopeat with a low percentage of fibres. It is enriched with bat guano, perlite, endomycorrhizas and worm humus. You can start growing immediately. No need of adding fertilizers during the first couple of weeks. Your crop will benefit from natural properties of this mix. Pure Superior Light Mix is ideal for fertilization, stimulation and protection. It is suitable for all types of cultures, outdoors and indoors. Perfect for short-term and seasonal crops.

What do you think I must do with each of them?

 

[AutoWonders]

I don't believe there can be a nute burn.

I was looking at the second to last pic, the leaf tip looks like it's burned. Can't see the other leaves. You might be good.

 

[Arthur]

Yep looks like overfeed to me as well, and transpiration issues. Your humidity is causing the leaves (tiny little fragile leaves) are having to work overtime to move moisture up and out. This can also lead to a false overfeed, as the plant is taking up more fluids and thus more nutes than in a environment that is closer to on spot.

That's a lot of sour cracks in coco.... my current SC is in the middle, 4x4 tent

 

[lessonslearned]

Yep looks like overfeed to me as well, and transpiration issues. Your humidity is causing the leaves (tiny little fragile leaves) are having to work overtime to move moisture up and out. This can also lead to a false overfeed, as the plant is taking up more fluids and thus more nutes than in a environment that is closer to on spot.

That's a lot of sour cracks in coco.... my current SC is in the middle, 4x4 tentView attachment 1026229

Shall I obtain some FloraKleen then?

 

[Waira]

They are not liking that coco mix,... guano is too general a term, many kinds, different NPK#'s... most are heavy P, and/or N, low K, but it depends and varies a great deal,... I see some N-toxicity happening,... fading lowers,... something is universally off, either the nute ratio is not to SC's liking (a lot of tolerance variance with auot's concerning nutes) and/or the pH is off,.... Coco cannot be run like true soil, or you will have a shit-show forthcoming,...A lot of do's and don't's with coco! Much of it relating to it's physical properties, and especially the CEC (cation exchange capacity)...
I see no info about your water pH, TDS/EC, your inputs pH and ppm's, and the run-off pH and ppm's,.. coco should be run with 15-20+% run-off each time you water/feed (never water alone Ca-Mg at least, or the CEC may get screwed up), weakly, and often, that's the whole gig with coco, it's more like hydro than true soil in some ways,... You can grow monsters in small volume pots of done right though, but for hand feeding, you're going to take a beating in labor unless you plan to rig them up with drip or something,.. Monitoring the ingoing and outgoing pH and ppm's is how you manage your nutrient inputs and make adjustments, as well as prevent nute salt build-up...