I thought I had it all figured out

I believe this is the right section for such a dumb question lol.
Well here it goes... How do you water plants lol. I mean im doing a closet grow with 4 plants using scrog method and I was wondering how people contain 20% run off and not spill any on the floor/closet???

Sorry for the dumb ass question!

 

I guessed that part but that is as far as I got, how do I get it out of the trays?

Thanks