having seen how it is supposed to be used…why would you imagine putting it in water would be a good idea? Yes, you also need a water heater of some flavor
At your scale sous vide as @GroovyOctopusLabs suggests is probably your best bet.
1K word substitute for how to plumb with tankless water heater here: In hot water... - #7 by Photon_noir
edit: the ones without the timer are cheaper. I like the three speed version, but always seem to turn them all the way up, so I’m not sure why ![]()
note: they will not suction prime, and don’t like being run dry.