With fall fast approaching the time has come for us to begin preparing our ponds for the winter season. Here's a breakdown of what you should be doing to prepare your pond, fish, and plants for a healthy winter.

All summer long, you've enjoyed the tranquility of the water garden's beautiful foliage, sounds of cascading water and colorful fish eagerly awaiting a handful of food. The water garden didn't get that way by itself. You add the right kinds of plants and fish to create a balanced ecosystem. The water gardens we create look beautiful and sustain life because we work with Mother Nature. During the winter months, despite all outward appearances, the pond is active even when the water is cold or even frozen. Dead leaves, algae, insects and solid fish waste that have accumulated over the summer slowly break down during the winter months. This natural decomposition uses oxygen and produces small amounts of hydrogen sulfide, a toxic gas that normally never reaches a harmful level. Few water gardeners realize that the pond must be balanced in winter too. Fish, frogs, and other aquatic life are especially sensitive to poor water quality in winter. A build-up of leaves and other organic matter can cause an imbalance, reducing oxygen to dangerously low levels and releasing poisonous hydrogen sulfide. Use a net to cover the pond to prevent the accumulation of falling leaves into the pond. This will prevent the frequent overburdening of debris in your skimmer box. It is imperative that the debris not be allowed to sit in your pond during the winter months.

You should also reduce sludge build-up with a bacterial "cleaning" product like Pond Care Pond Zyme Plus or Microbe-Lift's Autumn Prep. Both products contain bacteria that digest dead algae and sludge that accumulate in filters and at the bottom of the pond. Both products are completely safe and help keep the water garden clean. These products will help to process the sludge and waste build-up that is hidden behind and underneath rockwork.

What should I do with my fish? Water gardens with depths of 24" or greater can leave their fish in their pond all winter long successfully providing they've followed the guidelines set forth previously in this article. Hopefully you have been feeding your fish well with a high protein food this summer to allow them to build up a reserve of fat to help them through the winter. Once the water temperature reaches the low sixties you should decrease the amount of food given and feed one to three times per week. At this time provide a food with a protein content of 25 to 32 percent. A wheat germ based food is good at this time as it is easily digested. Once the temperature drops below 50 degrees stop feeding altogether until spring when the water temperature is consistently above that same level.

There are a few other considerations to over wintering your fish in the pond. The first is that as organics decompose in the pond they can produce toxic gases that could be trapped in the pond if it is covered by ice for more than a few days. It is important to keep a small area free of ice so that these gases can escape. One way to accomplish this is to use a pond heater or deicer. Make sure you get an energy efficient and thermostatically controlled product like the Thermo-Pond. This heater operates at only 100 watts compared to some other products that operate at 1000 or even 1500 watts! Another option to keeping a small hole in the ice is to operate an air pump with an air diffuser to assist with keeping a hole open in the ice. The constant motion of air bubbles through the water will prevent the ice from forming.

What do I do with my aquatic plants? Long after the impatiens have been pulled out, water gardeners are still hoping for that last lily bloom. We want to squeeze every leaf, bud and blossom out of our aquatic plants before winter. Unfortunately, cold weather often comes before we've trimmed the cattails or pruned the lilies. If you wait too long the leaves will fall off and rot in the water. Trim bog and march plants before frost hits. Pull out the hardy water lilies and trim off all the leaves. Put all the potted plants into the deepest area of the pond to prevent freeze damage. Check with your supplier for specific requirements for wintering your aquatic plants.

Should I leave my pump running all year? As a general rule, I don't recommend operating your pump through the winter. We usually stop the pumps around the middle of December. Place your pumps, filters, and other mechanical equipment in an area where they won't freeze or remove them completely from the pond. As water freezes it expands and could cause internal damage to your equipment. Prevent this by placing your pump below the freeze line in your pond. If that isn't possible then remove the pump and keep it submerged in water to prevent the seals from drying out.

Performing these simple maintenance procedures ensures you that you have done everything you can do to prepare your pond, fish, and plants for another successful season.

WINTER PREPARATION

With winter setting in many pond owners have begun taking the necessary steps to ensure that their fish, plants, and pond equipment is winterized. In the last issue we briefly discussed fall preparation for your fish and plants. Let's discuss more specifically what should be done do your plants, and equipment for a successful winter and the beginning of a successful spring.

By this time most leaves have fallen and hopefully not into your pond. Be sure to remove as much debris from the pond as possible. The accumulation of this debris will decrease the oxygen levels in the pond. The decrease in oxygen could have harmful effects on your koi and other fish. If you have a Purifalls waterfall/filter box then now would be a good time to clean the mats located within the filter. With biological activity at it's slowest this is the best time of year to maintain the filters.

Depending on the climate you may or may not want to operate your pump and filters during the winter months. If the temperatures stay mostly above freezing then it will be beneficial to keep your pump and filters operating through the winter. The bacteria is not active at this time due to the low water temperatures, however, it will stay alive because your pump will be pushing oxygenated water through it. Once the water temperature begins to rise in the spring the bacteria will begin to work immediately keeping your pond cleaner and algae to a minimum. If you decide to operate your pump during the winter then I recommend keeping the flow rate minimized. Some ways of accomplishing this are to turn off bottom drains, turn the flow rate down on your pump, and if possible, placing the intakes to your pump or filter at mid-water level. Intense circulation in the winter can chill the water by exposing warmer water at the bottom of the pond to below freezing temperature water on the surface, which can potentially lead to the death of your fish.

One issue of operating your pump and filters during the winter is the potential of damage to these components should the power be interrupted for extended periods of time. Some systems are designed to allow the water to flow back into the pond should a power outage occur. If you have a check valve on your system consider removing it during the winter so that it doesn't prevent the water from flowing back into the pond.

You may decide to remove your pump(s) and filter(s) from your pond during the winter. Since cold water contains for oxygen than warm water and the respiration of the fish is slower, you shouldn't need the circulation and aeration that the pumps and filters provide. The bacteria in your biological filter is not providing any benefit during the winter so the only reason to operate your pump and filter is to keep the bacteria alive and for aesthetics. If you decide to turn off the pump for the winter be sure to drain all the equipment and plumbing lines. External filters, UV's, and external pumps should be drained completely. Submersible pumps need to be kept at the deepest section of the pond to avoid freezing or be placed indoors. If you remove the pump from the pond remember to place the pump in a bucket of water to prevent the seals from drying out.

Any plants in the pond need to be cared for based on the type. Any oxygenators and/or submerged plants should be left completely submerged at the bottom of the pond below the ice line. Foating plants such as water hyacinth and water lettuce, however, should be removed from the pond completely as they begin to die off from the cooler temperatures and frost. Be sure not to leave these in the pond as they will decompose and rob the water of needed oxygen for the fish.

Hardy lilies and marginals should be cut back and placed in the deepest part of the pond- assuming your pond is 18-24" or deeper. This should be done after the first frost. If your pond less than 18" deep, remove these plants and place them in containers filled with water in an area that will not freeze.

Other hardy water plants such as iris, sweet flag, grasses, cattails, rushes, etc. should be left in place to overwinter regardless of pond depth. I recommend cutting back the foliage on these plants in the spring rather than in the fall.

As for all tropical plants, they all must be removed and placed in water that will remain above 65 degrees . You should do this before the first frost. Most tropical pond plants make great indoor plants too so bringing them indoors extends your hobby throughout the winter. Taro and canna are some of the more popular plants that are tropical.

By performing these tasks you will ensure that your plants, fish, and pond will live through the winter and thrive the next spring.