First my quick story - parents recently divorced and mom was going to loose the house...my wife and i bought it from her and she still lives with us, but she never learned how to run the pool - that was dad's job. Now we seem to have a problem and being a pool newbie i'm unsure where to start.
The 10,000 gallon in ground pool has about a foot of water in it. The hot tub is right by the pool and i believe, when they are both filled the tub runs into the big pool.
The pump and the multi valves are above the water level in the pool. Although the pump pulls water just fine when taking water from the Spa, when turning the valve to pull from the pool, i just get slow stream - like the pump is pulling in air from somewhere. It's like it pulls for a second or so, the pressure valve on the filter goes up, but then it looses any steam and just pulls a little bit.
Is the pump not strong enough? Is there still a blockage that we haven't fixed or should I now begin replace the seals? Help me please

Thanks in advance.
Tracy