250 ml should be enough for at leat 5-7 days. I do it like this with lil seedlings. i give tem every day a small amount and soe foliar feeding that means 20 ml water and some spraying with water and aloe( before Light turn off)
correct waterregime is for me one of the hardest thing to learn indoors.
I messed up my first indoor totally with overwatering
To train your skills you can go with the Potlifting or pot weighing method.
That means.... fill a similar pot with ry soil and try to remind that weigh ( of put it on a scale).....here you have your refeernce weigh
if your pots with the plants and the water reach the weigh of the dry,,, you can water again
Its good you took plasticpots, because here you get a good drinage.
Smartpots are better for the Plant, but they keep the humidity and water very good inside ... bad if you overwater
Iam sure you get used to your wateringregime, by using this technic.
I know some more , if you are interested.