Do spray balls work off wimpy march pumps?
No. Most of us use a submersible utility pump in the 1/3hp range (depending on the spray ball).
Ahh that makes sense. Do they make temperature rated submersibles then if you wanted to heat the soak up a little?
Not sure, but you can count on spending big bucks if you find one.
There are a couple threads around here about the max temp debate for these low cost pumps.