Help: Light Green Spots On Seedling’s Leaves

[Drakka]

Hi everyone!
I’m at my first indoor growth, and as a lot of other newbie growers i’m often worried about doing things the right way...
I got a 60x50x140cm DIY box, I had to place it in a room where temp and Rh varies depending on the daily weather, as I got no other rooms to place it.
Light: Spiderfarmer SF 1000 (24 inch away from plants)
Reflective Material: Car Sunshade
Pot Size: 14 L
Grow Medium: BioBizz All Mix
Ph: using a Liquid Tester and Ph- from BioBizz, around 6,5

I got 2 pc fans but had to shut them off because of low humidity in the first days (around 41 RH).
I bought a Humidifier that I need to clean and fill of water every 4 hours; when on, RH is between 55 and 70, but as I wake up late, it lowers down to 41/43 in the morning.
Temp differences between day and night are always small (Around 27 during the day and 22/21 during the night)

I’m growing:
- 1 Jack Herer Auto FastBuds
- 1 Blackberry Auto FastBuds
I know, it’s stupid to grow a Sativa with an indica in the same small space but, too late

I’m now in the seedling stage, but i’m starting to see light green spots on some of the first leaves, some of them are even deformed (like you can see in photos below)
At first I thought it was because of overwatering issues that I had in the first days, so I started waiting the soil to be dry at the top before watering it again, but the problem hasn’t stopped.
I’m giving them 250 ml of water per plant with 2ml of BioCanna Rhizotonic every 2 watering.
I saw a few little red spiders on the window I usually open to lower the temp, but never seen them on the plants...
I would be very grateful to be helped by someone that has more experience than me.
(Sorry if accidentally made some writing errors, English is not my mother tongue)
Thanks for the help!

 

[Pbass]

Does Biobizz include cal/mag @Drakka? If not I'd venture a relatively uneducated guess that that's the start of a cal/mag deficiency. You might also still be seeing a bit of residual overwatering effects, it seems like what you did a week ago is what you see this week in growth. They look pretty darn nice to me, after a while and a certain volume of plants your standards and concern starts to lower just a bit lol

 

[Drakka]

Does Biobizz include cal/mag @Drakka? If not I'd venture a relatively uneducated guess that that's the start of a cal/mag deficiency. You might also still be seeing a bit of residual overwatering effects, it seems like what you did a week ago is what you see this week in growth. They look pretty darn nice to me, after a while and a certain volume of plants your standards and concern starts to lower just a bit lol

Firstly, thank you for helping me !
As I found out, All Mix lacks of Cal/Mag.
How can I solve this problem in such an early stage?
I’ve read here on the internet (such a difficult place to find single answers, lots of contradictions and obviously, different opinions) that nuts and supplements can’t be introduced till the second week... now, my cuties have almost 13 days from sprouting, so it should be fine to start the feeding in a few days (?)
My question is, as these signs of probable deficiencies were visibile since the the first week, how could someone solve it or prevent it without waiting to be ok with feeding?
Maybe the deficiencies are due to my past overwatering issues, so the simple answer is: next time, obviously, don’t overwater it and no sign of deficiencies should be visible (?)
Or maybe, it’s because i’m using a liquid Ph tester, not that accurate?
I’m laughing at myself!
It’s so funny, after all of my thoughts and worries, to read your answer and realise that i’m tripping that much about things that a long time grower would be chill about
I’ve asked the same questions to a person I know that has been growing for a long time, he literally laughed at me and said “Just chill, it’s your first grow and they’ll be fine...”
So yeah, i understand this... maybe i’m staring at them too much

 

[Pbass]

maybe i’m staring at them too much

I can't help it! I love going in first thing in the morning and just looking around, seeing how everyone is doing. Every day for over a year now!

I'd guess what you are seeing is a bit of overwatering effect from before showing up now. Someone told me often we are looking this week at the results of what mistakes we made a week or two ago in soil...which gives some time to react and adjust! Regardless if its the watering or deficiency, it's been proven to me during my time here that cal/mag is certainly important for indoor grows, so while your water may be giving your plants what they need right now, it won't have the levels to sustain them as they grow and will need to be introduced. I'd do it just like I do with nutes at that age, work it in a bit light strength to start and eventually ramp it up till you feel like you have enough foliage to be at full strength.

 

[Drakka]

Understood!
So, what product would you advise to prevent these potential deficiencies?
A Cal/Mag something from any brand?
I currently have an indoor try pack from BioBizz (BioGrow, BioBloom, Top Max)... I read that Top Max contains some Calcium and Magnesium (tired of writing Cal/Mag ) but from what you wrote, I think I’ll need something more... fact is, I already spent a lot for the whole set up.
Thank you once again Ian Anderson!

 

[Drakka]

Bad news, this morning, after yesterday’s first session of LST, my indica is showing some clear yellow tips on her new growth leaves....
I need help, once again!