These are 3-gallon pots. Here's a picture of my trays after watering. For me I can water every 4-7 days or unless I see leaves drooping (i will do this at first just to see how long it takes before the plant needs water, then from there I can plan out approximately when to water). Having one of these also helps
At least the temp and humidity, the barometer came with this as 1 piece, but you can get just a simple temp and humidity gauge from just about anywhere. This one I hang in my closet
Less than $10.00.