Hey wetshoes
I found out what was wrong with my system... turns out it was not a clog,
it was actually a very small air leak.
we had forgot to put the O-rings (rubber gaskets) in our attachments ( & possibly one of the hoses wasn't exactly threaded correctly)
anyway, this tiny airleak ( coupled with the water level not being overly high, but just at minimum required level), caused the system to not prime correctly

so I guess I'm saying, check all hoses and connections for possible leaks because it could really be that you are just drawing in some air