Pond Tips - Desert Ponds

 

In Arizona, with the intense sun and dust storms, a filter of approximately 5-10% of the total pond volume seems to work best. For a 1500 gallon pond, that comes to 75-150 gals. This may seem like a lot, but pinching on the filter size always causes maintenance nightmares later.
Blown in dust circulates around in our ponds, is seem by the sun, and the algae spores in the dust sprout.
Once there are millions of the specks of dirt that are becoming larger algae balls, our ponds start turning green. I've seen ponds that looked like pea soup.
In windy desert areas like Arizona, physical removal of the dust is an absolute necessity. This is why small canister filters don't work here. Open box gravity filters work best here. Cloth final filters work extremely well to remove the dust. These must be cleaned as often as they become plugged with dirt. Simply hosing them off works well.
Cloth polishing filters in open box designs can be built so the water will flow over the top of the cloth filter frame if it gets plugged, instead of blocking and stopping water flow. That is a big problem with pressure filters. Open box filters are very easy to maintain, just lift the vertical pads out and hose them off as needed. If designed with Matala plastic pads, they last indefinately. I've inspected 20 year old Matala pads that were as good as the day they were installed. Pond filter cloth typically lasts about two years due to the abuse from handling and hose cleaning. It's cost is about $8 / square yard.
The second function of a pond filter is based upon the total weight of the fish. If you limit the number of fish, the filter requirements are reduced as well. Remember that ten 4" long fish will grow to the equivalent weight of 200 4" fish within a couple of years. It is the fish weight, not the length that counts.

We use bio-filtration to remove the fish waste, which is ammonia, a super food for plants.
Many problems start with too much ammonia in the water. Limiting the fish population reduces the ammonia and the problems. A suitable pond filter converts the ammonia to a harmless form.
The size of the filter also determines how often it will need cleaning. Larger filters have greater dirt holding ability. They also have a greater area for microbe colonization and greater ammonia removal. This allows you to have more fish and still have a clear and healthy pond.

If ever, your ammonia levels register too high, an immediate partial water change is needed, and the addition of chlorine eliminator too if you are using city water. Replacing 30% of your water will reduce the toxic level of ammonia by 30%. As water evaporates and is replaced, the dissolved chemicals stay behind. Those are the same white powdery residue left in a glass of our water that has evaporated away. Regular partial water changes are good as this removes the undesireable levels of chemicals, minerals, salts, etc. Non-Iodized salt is good in our ponds. A level of .003 on a hygrometer is ideal. The fish don't mind it, but above .006 the plants can suffer.

Details of several pond filter designs are available free upon request.