Help with seedlings

[Gurnsy]

Hey guys first timer here,

i noticed 1 of my 4 babies has started to show yellow spots. I noticed last night she was looking a little weird but thought my eyes were playing tricks on me. This afternoon these yellow spots have showed up. From my research on gwe it looks like yellow leaf spot. My other 3 seedlings are all looking healthy. I had very high hopes for the seedling showing the yellow spots as she popped up a full day before the others on the 8/3. now she has been overtaken in size by the others.

My tent has been abit humid sitting at 70% as it’s been raining today.

Here’s some info of the environment:
4x4x6.5 tent
1000w ballast mh bulb dimmed to 60% and sitting at 50cm from the girls
8inch hyper fan on a carbon filter sucking through a cooled hood
6inch cultiv8 fan for intake
fan below the light to circulate air
1 gal pots
50/50 coco and perlite mix
temps sitting from 70f-80f. Sitting around 78-80f most of the time

Germinated in jiffy pots and transplanted into 1gal pot
10/3 given 200ml each of ph 5.7 water and great white beneficial bacteria
11/3 250ml ph 5.6 and e.c 1.0 each of 20% strength seedling mix of general hydroponics. Made 2L of the mix
calmag 2.6ml
micro 0.21ml
gro 0.10ml
bloom 0.10ml
diamond nector 0.26ml
flora blend 0.52ml

12/3 (today) given 250ml each of the same mix given above.

any advice would be greatly appreciated. Thank you in advance

[Campesino]

Pretty confident that is Cal deficiency caused by low pH. Just dealt with similar issues myself in exact situation (Jiffy into 50/50 coco/perlite). In my case they responded well to raising the pH to 6.2-6.3. I also hit them with a Cal Mag foliar a couple times. They showed symptoms again when I tried to lower the pH again. They have since grown out of it and are doing well. I am going to start working pH back down.

[Campesino]

Are you in the future? it is March 5th in my time zone
Also, I really recommend to always add Cal Mag to water in Coco. Always, until the final flush...Didn't see it in the water on "10/3". that could be part of problem
Finally, are you getting run-off at those levels? I am giving about as much to one of mine in a 1/2 gallon pot...And thinking it needs more. Your Coco looks pretty dry.

[Gurnsy]

hahaha shit fully mixed up the dates some how lol! Should I possibly try giving it a Foliar spray with cal mag in it ? I was going to give them a water of just ph water drain to waste 20%. Maybe I should add some calmag in it aswell and see if that helps. I used premixed coco and never added any water to it because I was scared of over watering them since they are so young, that’s why it is so dry. I’ll try upping the ph to 6.2-6.3 as well

[Campesino]

Always Add Cal Mag to all water that touches your coco!

OK, You are going to have to add a LOT of water! Coco with perlite can be kept pretty wet because it retains sufficient oxygen with perlite. All the Coco in the whole pot should be soaking wet every time you water.

[Campesino]

As Nebula advises... you should water until 20% run-off on flush cycles (No nutes, just Cal/mag) when applying nutes you don't need as much run-off, but it is a good indicator that your coco is properly wet. You do not then need to wait for it to dry... if you have 50% Perlite, you can water every day. I do not let my coco get dry ever.

[Gurnsy]

Thanks for the advice ! Just made 1L of ph 6.3 water with 1.3 of calmag and fed between them. Didn’t see your reply before I did that otherwise I would of made more. I’m gonna give them more water in the morning when I get up for work.

[D.A.A.S.69]

Morning Gurnsy, just a reminder, just make sure your light is plenty high, if not your asking for trouble.
A lot of us on here use a couple of cfls, when they are young, just so we want burn them.
Good Luck with yours.
Seedlings don't need much light at all.

[Campesino]

No problem... I am always happy to help.
Coco is great because of this watering aspect. You can get pretty rapid growth.
I think I posted this for you before but here is a link to my new grow. the are currently at day 21 (well, five of the six).

https://forum.growweedeasy.com/forum/growing-community/174622-coco-led-6-manifolds-grow-2