Hello, I have an attached spa to the pool (see picture). My question is how to properly run the water in the spa. Is the spa's water supposed to spill over the spillway into the pool in order to return to the filter? If the spa's water does not spill over the spillway then how the spa's water is returned to the filter to be filtered? My spa's water currently does not spill over the spillway into the pool but the water in the spa looks bad like unfiltered water. Thanks in advance for your help.