By Patrick Simmsgeiger, Founder of DWI
Part of the commitment you make when you decide to install a water feature is maintenance. In many respects, the smaller a water feature, the more maintenance it requires (per unit of size). Forget about relying totally on chemicals and an occasional cleaning. Water features aren’t pools, especially when you include fish.
Filtration and Aeration
Filtration and aeration are very important with smaller features. You want a minimum depth of two feet with constant circulation and filtration. Waterfalls or circulation pumps should pump water through a properly sized sand media filter. The media in the filter should include two-thirds sand (12 to 16 mesh) and one third activated charcoal. The filter will remove organic contaminants and keep the water clean. Waterfalls can increase oxygen content as well. If you don’t have a waterfall, install a fountain-type aerator or injector-type aerator to go along with the circulation system.
An alternative to a media filter is a bio-filter, which is essentially a gravel bottom that acts as an intake through which the water circulates. Beneficial bacteria (aerobic) will become established in the gravel and keep the water both clean and fresh. At least two thirds of the feature bottom should be covered with a foot of gravel over perforated drain lines that return the water to the pump. Use river rock or granite. Avoid limestone.
Water pH can be a problem, especially for some of the beneficial bacteria on the market. Microbes prefer 6.5 pH. It’s not unusual for public water to run about 8 pH in the Southwest. It might also have a salinity problem. Test your water source just to be sure. Alkaline water can be adjusted with small quantities of acid. Salinity can be adjusted to a degree with gypsum (calcium replaces the sodium).
Caring for Fish in Your Water Features
Some algae (filamentous) are actually preferable for fish. Consult fish suppliers for the right number and combination of fish to stock water features. Avoid over-feeding fish to avoid organic buildup.
If you stock your water features with fish, provide access for observers to enjoy watching the fish, such as bridges and decks. Visible enjoyment should be balanced with audible input, so include waterfalls and fountains. Lighting is very important to water features at night.
Lake larger features, the safest bet is a natural balance among fish, beneficial microbes and nutrients. In the case of small water features, this weighs heavily on filtration and aeration. Chemicals can’t replace basic mechanical measures. But occasionally, a clarifier or dye might spruce up your water feature now and then.
Dyes can improve the appearance of shallow water features and slow establishment of aquatic weeds. Do not paint the bottom of water features a dark color that will absorb heat. Make them reflective to keep water cool, and avoid rough concrete surfaces in favor of smooth surfaces for the fish.
Enjoying Your Water Feature
Water features provide a type of enjoyment that has lasted for millennia. They are now available to a greater number of people. Keep in mind the thinking of our Buddhist predecessors, pay attention to the “now” and you will assure the success of the future.