I don't know if you could feed the garden hose into the Intex pump and sand filter without starving the pump. You could draw directly from the creek using the pump and sand filter, but I think the way you are doing now is best. You can get a very fine filtering bag from Duda diesel or Slimebag that should capture most of the silt from the creek. You could get a longer section of intake hose and hang it over the side instead of connecting it to the pool inlet, then you can start filtering the water as the pool fills. I would attach the pump inlet hose to a manual vacuum cleaner head with the pole attached and use a bungee cord to keep the pole from slipping under the water once you have at least 6" of water in the pool. Connect the filter outlet to the pool as normal. Fill the sand filter vessel and the pump strainer pot with water to prime before turning it on. Keep an eye on the pump until it has worked all the air out of the system. When the water is close to the height of the pump inlet, turn off the pump and set the sand filter to closed. Connect the pump inlet hose to the pump and disconnect the inlet hose from the vacuum. You will loose a little water during the process. Continue filling the pool. Once the inlet is submerged turn the pump back on and start balancing the water. You can add a large jug of plain, unscented bleach or chlorinating liquid to the pool once the pump is running.