Been perusing the threads about switching to 2 speed pumps for energy savings but am wondering: our pool (details in siggy) still has its original late 1960's/early 1970's plumbing - one skimmer, one vacuum inlet, one return, the main drain was shut off by previous owner (prob. because it has the noncompliant cover), valves for adjusting the flow are frozen in place. So circulation is already sub-optimal with the current pump setup. In this case, would it still make sense to change to a 2-speed pump or with our poor circulation should we stick with the current pump?