You don't need them.
That's right. You simply don't need any of the above to have a healthy pond. Regardless of your location, climate, and pond size, it's easy to have a beautiful pond with crystal clear water and NO hardware by creating natural balance. Here are a few simple steps to achieve balance:
Now leave it alone. In a matter of days, the water will be clear. If it isn't, add more plants.
If you are trying to balance a problem pond, turn off all your devices and resist resorting to chemicals. The more you do to interfere with nature, the more you will have to do. Any improvement would be short-lived anyway.
Using a pump to recirculate pond water isn't necessary to pond health, but many people want a waterfall, fountain or spitter. If you use a pump, be sure to elevate it above that wonderful sludge you are creating on the bottom or you will be recirculating the sludge instead of the water.
We realize that these recommendations are contradictory to many sources of pond information, but we only ask that you try natural balance first. If it doesn't work (and it will), you can still invest in expensive hardware.
For more detailed information, see Clear Water.