Trying to make a feeding tube to attach to my supply water line

[RPatsula]

Hi, I was watching an episode of tanked from last season and they made a feeding tube that they attached to the water supply line at the sump for a saltwater aquarium. I was wondering if anyone here has done that. i'm in a wheelchair and would like to be able to try and feed my fish, so this looks like a great way to do it.
I went to all the home renovation box stores but none of them have anything. My supply line is 3/4'' pex. What i would like to do is come off of it with a Wye then put a gate valve then somehow go from 3/4'' to 1-1/2'' or 2'' pipe then have a screw cap to seal the feeder tube. Can anyone recomend a plumbing store here in edmonton or an online one that might carry that stuff.

Tanks for your help
Rick