Just a clamp should fix the leak, no need to use silicone.
Very nice job on the DIY clear spraybar!
Did you glue or solvent weld the 90° fittings/connections together where they go over the rim of the tank? Hopefully you will say yes. I'd hate to see them come apart and get water everywhere but in the tank.
Eheim Pimpette #270
Eheim Pro II 2028; Classics Series -2215, 2217, 2260, 2262; Pro 2229 Wet/Dry