If your main goal is saving energy, you can run the condenser tubing straight to the pool water and let mother nature do the rest. The simplest version of this would be merely submerging the tubing in the pool. A more modular version would plumb in as a thermosiphon, like this but mounted vertically (obviously adapted to your pool plumbing):
Even with the 55 gallon drum setup, the coil could be placed in the drum and plumbed to thermosiphon. An advantage to this idea: you could draw hot water out of the top of the drum and spray it in the air on its way back to the pool as a secondary cooling method.
With the large body of water acting as a buffer, the indoor-outdoor temperature split would be closer than you could achieve with an air-cooled condenser most of the time. However, the heat has to go somewhere. If you are dumping 4 tons of heat into the pool all day long, a secondary cooling system will be needed unless you like a hot swim.
Using less watts than a manufactured unit isn't too difficult, but in this case the least is the most, so to speak. The more passive and overbuilt your design is, the better the odds are stacked in your favor. Be creative and criticize your own choices before you commit.