Lemon Tree - Leaf damage

[vrm]

Hello,
 
I have started a month ago some lemon from seeds along with my peppers. they grew really nice until some spots appeared on the leaves. I was not worried as I thought they are burns from the light because one day before the spots I sprinkled the small trees with a solution of hydrogen peroxide (1 part peroxide, 1 part water) because I noticed some white fungus starting to grow on the soil. 
 
Initially I thought the water droplets acted like a light intensifier and burned the leaves. Now it seams like the new growth is coming out with an yellow tint and I started to worry.
 

 
 
Have you seen this before? Is there anything I can do o fix it?
 
Thanks!
 
 

 

[CaneDog]

I think it's likely that the H2O2 burned the leaves - especially if they weren't kept out from under the lights until dry after spraying.  If it all suddenly appeared the day after spraying, I'd strongly suspect it. 
 
I don't think the new growth looks bad. It's not uncommon for new leaves to be lighter, at first, than older, established leaves, and then darken as they grow out.
 
Good luck with them.  Your pepper starts look great!

 

[vrm]

Glad to hear this. You might be right about the new growth as it started to look a bit better day after day.

I was worried as I had some fungus problems around my peppers and I thought it might be something related.

As of the peppers I have some grate looking ones especially as they were sowed 1st of Feb.