The first year is often the most difficult for pond owners. Your pond may go from crystal clear one day to green the next. The water quality ups and downs that come with building a brand-new pond are commonly referred to as "New Pond Syndrome." Ponds need time to cultivate the beneficial bacteria that balance the ecosystem in the water and jumpstart the nitrogen cycle. Learn more about New Pond Syndrome and what you can do to prevent this common issue.
The Nitrogen Cycle
Ponds have their own way of naturally filtering small amounts of waste in the water–the nitrogen cycle. Fish waste and organic material, as it decays, release ammonia into the water, which in too large of quantities can quickly harm the fish and deplete the oxygen level. The beneficial bacteria turn this ammonia into nitrite and then into nitrate (which is less harmful). Aquatic plants absorb this nitrate, using it as food.
The beneficial bacteria grow on the liner, rocks, gravel, and other wet surfaces. They also needs oxygen to survive which is why having aeration is important, especially in the summertime. Beneficial bacteria are aerobic (requiring oxygen), and there are also anaerobic bacteria (don't need oxygen) in the pond. The anaerobic bacteria often live in the bottom of the pond where the oxygen levels are the lowest and slowly break down debris. These bacteria aren't efficient and, alone, aren't able to break down the debris before the ammonia harms fish or fuels and algae bloom.
Brand-new ponds often stay clear until fish are added. The New Pond Syndrome often results from adding fish or occurs after a storm. Fish increase the nutrient load for the pond, with any uneaten food and waste. Lawn and plant fertilizers contain high levels of phosphorous, nitrogen, and other nutrients that algae love. Without the beneficial bacteria able to break down this waste, the algae have an all-you-can-eat buffet and bloom. They can quickly turn a pond from clear to green with the right conditions.
While you may be tempted to add fish to your new pond immediately, this can trigger New Pond Syndrome. Your pond needs time (ideally a few months) to start building up good bacteria colonies. When you add fish, try adding one or two at a time to give your pond time to catch up. If you start adding fish and there is more waste than the bacteria can handle, it can lead to algae blooms.
Your existing pond can also suffer from New Pond Syndrome if you overclean and remove the beneficial bacteria. When doing a water change or deep cleaning, do not scrub the liner, rocks, or other areas where the bacteria could cultivate. A total water changeover with deep scrubbing often seems like the cure for a green pond. When you remove all of the pond's bacteria, you have to start from scratch, and the pond has to build up its bacteria colonies again, which takes time.
What You Can do to Avoid New Pond Syndrome
Test the Water
If your new pond is suddenly green, the first step is to do a water quality test to see what's happening. The test will tell you the exact levels of different contaminants and the pH. While the most common cause of new pond syndrome is adding fish before the pond has cultivated bacteria colonies, you could have excess nutrients from other sources like fertilizers.
Remove Chlorine and Contaminants
When building a new pond, once you add water, it needs to be treated with a de-chlorinator. If you have an existing pond, whenever you do a water change (full or partial), you need to treat the tap water to make it safe for your fish and plants. The smartpond Chlorine Remover plus Conditioner removes chlorine and other contaminants in the water that can harm your fish and plants. The conditioner also helps to destress your fish and build up their protective slime layer. Wait 24 hours after dosing the water before adding new fish.
Add Filtering Plants
The right aquatic plants can make the algae compete for resources. Algae need direct sunlight on the surface of the pond to bloom. Floating Plants take up this space and add shade to the water (which helps increase oxygen). Adding a combination of emergent (plants that root beneath the surface and bloom outside of the water) and submerged (grow entirely underwater) along with floating plants help to absorb the nutrients and naturally filter and oxygenate the water.
Use Biological Filtration
You can also help your new pond by adding biological filtration. The smartpond Pump Filter Box is a house for your pump and prevents debris from entering the pump and causing clogging. The Filter Box also contains bio balls which contain beneficial bacteria that can help filter the water as it passes through. It uses filter pads to mechanically filter the water too.
A brand-new pond needs time to adjust before it can handle large amounts of debris, fish waste, and nutrients from other sources. When a new pond quickly goes from crystal clear to green (often after adding fish), it's called New Pond syndrome. The pond doesn't have enough bacteria to break down the fish waste, and the overload of nutrients creates the perfect conditions for an algae bloom. When you build a new pond, it will take some time to cultivate the bacteria it needs to balance the ecosystem and have an efficient nitrogen cycle. You can help your new pond by using a chlorine remover to treat the tap water and add biological filtration.