Watering seedlings. Methods, times of day, how much water & time between watering

https://www.youtube.com/watch?v=hgtbNDlvs5kI explain the options, frequency of watering and using a water-can rose. Check your trays daily, lift to assess need of water, adapt watering to seedling size and the weather forecast. The bush tomato variety is Maskotka, I called it wrong. Water - I use rainwater if my butts have filled, otherwise tap water. We have some chlorine, no fluoride or aluminium.