How much to water a germinated seed in rock wool???

Im so afraid of over watering. After the seed germinates and i put it in rock wool to start its life, how much do i water it. I am going to be using a hydro set up, and im also not exactly sure when the seedling will be ready for nutes. The seed is in a rock wool cube, so do i just drip a lil tap water into the cube periodically?

keep an eye on it rockwool can dry out quickley just keep it moist, and wounldnt use any nutes for a few weeks. Dont forget to ph your water