What is the suitable soil humidity for growing?

ive got some 4 gallon smart pots from nirvanashop and im wondering what is the humidity of soil is best to my plants, how many liters of water should i irrigate my plants per three-four days?
thakns !

Make it damp when you plant - not wet. Water when it gets pretty dry. Water slowly until you get some runoff. Exact amount will depend on many variables like RH, soil components, temp, etc.

I use about 1/2 gal per 3 gal pot every 3-4 days.

1 to 1 1/12 gallons of water for a four gallon pot every 5-7 days should be enough till the plant is about 1 to 1 1/2 months old then in flowering and as the plant grows larger you may need to water more often. If you can stick your finger in the soil up to the knuckle and it feels dry then its time to water. Dont water it too much or you'll have problems.