I use these inline to separate the tank from the trays
5 Pack (25 Total Fittings) Orbit 1/4 Inch Barbed Drip Irrigation Tubing Shut-off Valve - 5 Pack
https://www.amazon.com/dp/B071QWYMPB/ref=cm_sw_r_cp_apa_i_NE.tEbH6SQBVZ
The tank itself uses its own shut off valve also
I don’t use these for leaks.
I put them in so I could take out individual trays and clean or work on them.
Also, if any plants finished before other ones I can take just that one plant out, flush it, then put it back under the lights but not in the tray to finish.