Take a deep breath, you've got this.
The #1 thing - that i've personally learned - with Calatheas
is they are ALL different, so you really have to pay attention to what does and doesn't work for yours specifically.
Water: They Typically prefer filtered, or you can leave water out over night to let all the chemicals evaporate. Water when they are dry or almost dry on the top few inches of the soil. They DO NOT like to be soggy but they also hate the being dry.
Light: Medium Light I find is best. Anything direct will burn the leaves but if it's too dark, the leaves will be lack luster and loose the gorgeous patterns that made you fall for them in the first place!
65 ˚F - 80˚F
Humidity: High Humidity, 50% - 70%
Soil: I find they aren't too picky here (shocking I know). Regular house plant soil + perlite has always served me well - you can add some Peat Moss if you want to get fancy!
Fertilizer: Only during growing season (late spring, summer, early fall). You can use any houseplant fertilizer but my preferred method is leftover coffee diluted in water (leave out the cream and sugar of course)!
- Curling leaves - under watered
- Yellow and brown tips - tap water burn, switch to filtered water
- Brown edges - low humidity
Notes: If things start going south, DO NOT PANIC and don't do anything drastic. Plants live in the wild and are used to their environment changing and having to recover. Be slow and gentle and they will be thriving in no time!