disease Please help identifying these issues

[crystale]

I have a few indoor plants that seem to have issues and I would really need your advice.

First there's the browning of the leaves in the first two pictures. It's been affecting the plants for a long time and I'm sick of it. For example, in the second picture there's a new chili plant which has germinated and grew quite fine for a few weeks, but now the leaves are being affected by this issue.

Then, there's the third picture in which we may see some black spots.
I checked and there are no aphids around. What else might cause these issues?

I know that good ventilation might help the plants and I intend to move them outside as the night temperature have increased. But besides that, what else could I do?

 

[Marturo]

Do you mist them? Do you have a fan on them? What do the growing tips look like?
What is the air temp & Humidity ?

 

[crystale]

The temperature inside is around 20-22 Celsius for now as it is still pretty cold at night, humidity around 60-70%.
No mist, no fan, only some fresh air from outside once or twice a day. Anyway, they will be moved outside soon.
Regarding the growing tips, I will try to get back with photos.

 

[Marturo]

I know that good ventilation might help the plants and I intend to move them outside as the night temperature have increased.

I think you answered you own question. Fresh air, sunshine & mild temps should cure everything.

 

[crystale]

Thank you @Marturo ! Hopefully the plants will get better when I take them outside.