Who can resist the cool allure of a healthy fishpond sparkling in a lush garden? We are drawn to touch the shimmering surface on a hot day and be soothed by the silent movements of golden fish, our hearts stirred by the heady perfumes of water lilies. But so many of us try and end up with nasty green algae, foul smelling water and dead fish despite the expense and hassle of expensive pumps and filters and medications and changing the water over and over...what gives?
Whether your pond is a butyl rubber liner, a vinyl shell or concrete, fill it with fresh water from your garden hose...don’t use softened or recycled water as it is high in salt. Cover the bottom with 2 inches of rinsed pea gravel to harbor plant roots and crucial water purifying microorganisms. Let the water age for 3-5 days to eliminate chlorine and other additives. Sprinkle on the water a couple handfuls of ‘Sunniland Palm 8-6-6' fertilizer to insure ample nutrients for your water plants. Then add a cup or two of the beneficial bacteria and enzymes sold at most aquarium stores, like ‘PondZyme’, as they are remarkably effective at digesting the wastes that foul so many ponds. Skipping this last step to save money is a false economy....trust me!
Then buy a few bundles of the native warm water plant " Hot Water Cabomba", also called Fanwort (Cabomba caroliniana) and anchor them to the bottom of your pond with chunks of limestone rock.(The limestone helps keep the water non-acidic plus leaches out calcium vital to the water plants, snails and fish). This plant is not only beautiful but an amazingly effective living water filter! Drop some into an existing fouled pond and in a month you will see a big change in water clarity. I know of no other water plant that so effectively oxygenates pond water too.
Treat yourself to native white water lilies, or those lovely fragrant purple tropical water lilies as their roots will also cleanse the water and the pads offer shade. I use a stone to hold the tuber down in the gravel instead of growing them in submerged pots so the roots can meander through the gravel and absorb wastes directly as a living water filter. Native water plants like blue pickerel weed and those teensy floating duckweed plants add diversity and color while purifying the water and offering shade and food for goldfish.
I have found over and over in creating and caring for my clients’ ponds that elaborate filters and chemicals (vs. a simple pump for that soothing water sound) keep the ecology unbalanced by continuously filtering out the nutrients that the water plants need, while killing beneficial organisms that create ecological balance. The water in my front pond is now 6 years old and clear thanks to my water plants and snails.
Let this new pond age for 2 weeks so that the water becomes fully alive and oxygenated. Expect an initial algae bloom as the juvenile ecology gets established and coats the sides with an essential carpet of beautiful green algae your fish will later graze on. Now the fun part...adding the snails and fish! I never use koi as they tend to eat all the plants that are the primary "engines" of a healthy pond ecology. I instead buy goldfish, usually the cheap "feeder" goldfish that are fed live to oscars and other carnivorous fish. Or treat yourself to the fancy fantails and tri-colored goldfish. You’ll be amazed at how quickly they grow into sizable fish! Ordinary brown pond snails from a fish store are considered a nuisance by some indoor aquarium folks but are very effective scavengers of excess fish food and algae and fish poop. DON’T buy those huge ‘Apple Snails’ as they will likely eat every single water plant!
People’s own good hearts are often their pond’s worst enemy....it feels so nurturing to feed the fish daily, but that soon overloads the water with uneaten food that decays and sours the water and kills the fish. Better to let them graze on mosquito and other larvae and on the green algae you want to grow on the sides of your pond as a very effective water cleanser and oxygenator. A trick I learned from a commercial tropical fish farmer in the 80’s is to once a week drop in a few nuggets of dry cat or dog food instead of those expensive fish flakes...as they float and soften they give the fish something to strike and since they are a complete animal food, they act as a vitamin and mineral and protein supplement to the fish’s main diet of algae and larvae. Sounds weird but it’s cheap and it works! Plus pet nuggets seem less inclined to cloud the water.
No need to change the pond water, ever. But to prevent the build up of nutrients just use your watering can to now and then treat all your potted plants indoors and out to a deep drench of that vitally rich pond water. A very slow drip from your garden hose overnight now and then will keep your pond filled during the dry season.
As we get bounced about by life’s rough spots it is nice to come home each day and soothe our eyes and our souls with a cool quiet oasis nestled in our gardens. Treat your self to an easy way the Japanese perfected centuries ago...the natural way to pond peace.