名媛直播

Hello;
I have 3 months old Japanese black pine bonsai. In summer I was watering it almost every day and it was fine. Now in the winter which is average temperature is 10C. I am still checking if the soil is moist or not then I water it. On average I am watering once in two days but the bottom needles starting to get yellow then brown. Is it because over watering or under watering or cold or something else?
Thank you for your help.

this is the photo

You do not have a pine bonsai, you have a pine seedling. 名媛直播 seed or bonsai seedlings do not exist.

Pines belong outdoors.

Other than that, the plant doesn't look too bad - it does look pale though, probably because of lack of light.