1. How deep should the water in my pond be?

2. What can I do if the water in my pond turns green?

3. Do I need a filter?

4. What size pump should I use for my pond?

5. Is my pond a breeding ground for mosquitoes?

6. Is it important to add bacteria to my pond?

7. What are string algae and how can I get rid of them?

8. What is a U.V. light and how does it work?

9. What should I do to maintain my pond over winter?

10. What steps are necessary to start my pond in the spring?

11. Is it normal for my pond to be dark and cloudy in the spring?

12. Is it necessary to drain and clean my pond in the spring?

13. What kinds of aquatic plants should I have in my pond?

14. Do I need to fertilize these plants?

15. Can I have fish in my pond and how many should I have?

16. How often should my fish be fed?

17. What should I feed my fish?

18. Do I have to move my fish indoors for the winter?

19. My fish aren’t eating, what’s wrong?

20. Are the fish in my pond safe from predators?

21. How much time is required to maintain my pond?


1. How deep should the water in my pond be?
The deeper the pond the better! If your pond is deep, there is less chance of it heating up and causing algae blooms. To accommodate both plants and fish, three different depths are ideal. The first depth being between 6-8” for marginal plants, 18”-4’ for water lilies and lotus. Fish require a certain amount of open water in order to live over winter. For example: In Southern Ontario it’s advised to have a pond 3’ - 4’ deep if over-wintering fish. Check to see what the frost line is in your area to determine your pond depth.

2. What can I do if the water in my pond turns green?

Green water in a pond occasionally is normal, especially in a new pond. You may also see green water in the spring before your plants re-establish themselves. Prolonged green water or thick like “pea soup” water is a cause for concern and action should be taken to eliminate the problem before it becomes more serious. Contact your Pondhelp specialist for information on products that will help you eliminate this problem.

3. Do I need a filter?
Filtration is one of the most important factors in having a pond that is healthy, clean and easy to maintain. In order to have this, it’s crucial to have a properly sized and utilized filtration system.

4. What size pump should I use for my pond?
Your pump size is another very important factor in having good water clarity. Your pump works hand in hand with your filtration system and should be large enough to circulate the entire water volume of your pond at least once every two hours. For example, a 1000 gallon pond would require at least a 500 gph pump at the point of discharge. Aesthetically however, you may desire a larger pump to create a large waterfall or a large fountain that would require more water volume for ideal results.

5. Is my pond a breeding ground for mosquitoes?
Mosquitoes can only breed on still water. If your pond has a proper flow rate and the water is moving, this should never be a problem.

6. Is it important to add bacteria to my pond?
Some pond owners are able to achieve ideal water clarity with the proper use of plants and water movement, however it’s not an easy task. An easier way to achieve this is to add beneficial liquid bacteria products to your pond. These products when used properly, will eliminate toxic ammonia and nitrates, and dissolve fish waste and other organic matter that can accumulate in your pond.

7. What are string algae and how can I get rid of them?
All ponds will grow string alga and there are many different kinds. It’s a perfectly normal and natural occurrence in all ponds. In fact, alga is helpful as it aids in water clarity and is a good source of food for fish. Unfortunately, most people don’t like the looks of it in their pond. One thing that can be done to remove it is to physically pull it out of your pond. There are also a variety of products that can be used to safely keep the growth down. NOTE: An important fact to take into consideration is that string alga is a by-product of something in your water. It may be growing because of excess fish food, fish waste and decomposing leaves and plant life.

8. What is a U.V. light and how does it work?
U.V. stands for Ultra Violet. A U.V. sterilizer is a unit of ultra violet light that when water passes through the rays, bacteria is destroyed. A U.V. clarifier is a unit of ultra violet light that when water passes through its rays, bacteria flocculates and becomes trapped in the filter. The wattage output of the UV sterilizer or clarifier and the speed at which the water passes through it are critical to it’s performance. Be sure to match the size of the UV light to the size of your pond (total gallons) and regulate the flow through the light for the best results.

9. What should I do to maintain my pond over winter?
Cut back your aquatic plants and sink them to the bottom of your pond. Note that unless you live in a tropical climate all tropical plants must either be discarded or brought indoors. You should also drop your water level to accommodate spring run off. If you have fish, you must keep a vent or hole in the ice for toxic gases to escape.

10. What steps are necessary to start my pond up in the spring?
Relocate your plants to their original growing locations. Fertilize, divide and repot if necessary. Add water to bring your pond back to its proper level.

11. Is it normal for my pond to be dark and cloudy in the spring?
It’s quite normal for your pond water to be cloudy in the spring. Heavy spring rains stir up debris on the bottom of your pond. Alga can grow quickly in the spring but once your system is up and running and your plants start to grow again your pond should quickly clear. Liquid bacteria products can assist you in your spring clean up.

12. Is it necessary to drain and clean my pond in the spring?
There are good arguments on both sides of this question. Some people find it easier to start fresh each spring by draining, cleaning and re-establishing their pond. If you have a large pond, this can be quite a production. If you have fish then it would be necessary to keep the fish in some of the original pond water while you are cleaning and then introduce them back into the new water after it’s been cleaned and treated. Some experts say that by doing this you are interrupting the natural eco balance of your pond but others disagree. Of course it’s much easier to drain and clean your pond if you have a small pond and if you don’t have fish then that’s just one less thing to worry about. You be the judge!

13. What kinds of aquatic plants should I have in my pond?
All ponds should have 60% of it’s surface area covered by plants. A mixture of three different kinds of plants are necessary for good water quality. These would include oxygenating, marginal and deep water plants.

14. Do I need to fertilize my plants?
Yes, especially if you want abundant flowering. Of course not all plants will have flowers but in order for plants to be healthy and grow larger you really should fertilize them. Check with your pond specialist to ensure you have the right fertilizer for your water plants.

15. Can I have fish in my pond and how many should I have?
Having fish in your pond is a matter of preference. Fish add beauty to your pond and they can be helpful as they eat algae and help to clean your pond. On the other hand, some fish will eat your water plants and require a certain amount of care. The rule of thumb when deciding how many fish to have is one inch of fish for each square foot of water surface area. This is a loose guideline and other factors such as the total gallons of your pond, the flow rate of your pump, the size and type of filtration and the type of fish to be stocked must be taken into account when determining the amount of fish for your pond.

16. How often should I fee my fish?
A common mistake of pond owners is over feeding their fish. In general you should not feed your fish more than three times a week, and no more than they can eat within five minutes each time. Excess uneaten food pollutes the pond and creates toxic ammonia. Cease feeding your fish once the water temperature of your pond drops to 50 degrees or lower. Colder water temperatures slow down the digestive system of fish, making it difficult if not impossible for them to digest most fish foods.

17. What should I feed my fish?
Any of the commercially available foods that are formulated for pond fish will do. Koi have different nutritional requirements than common goldfish, especially in colder climates. For that reason choose a high quality food rather than the least expensive food.

18. Do I have to move my fish indoors for the winter?
In most cases, it is less stressful on your fish to leave them in the pond for the winter, providing that the pond was constructed with this in mind. Keeping your fish in a pond that is shallow in cold climates can be risky. If you must move them indoors, do so before your pond water temperature gets too cold. Be sure to provide plenty of aeration and water changes to your indoor holding tank.

19. My fish aren’t eating, what’s wrong?
It is common for fish to refrain from eating for a few days if your pond has been disturbed in some way, such as draining and cleaning. You can also test your pH, ammonia, nitrite and salt levels to ensure they are at the proper levels. If not it may be necessary to do a partial water change in your pond.

20. Are the fish in my pond safe from predators?
Some common predators to fish are the Blue Heron and the Raccoon. For the most part, fish in city and suburban ponds need not fear the expert fishing skills of the Blue Heron. However, large properties providing runways, and bigger ponds in the country should be aware. Netting your pond, using a decoy (as they are a territorial bird) and persistent shooing can help in deterring this bird. Please note that the Blue Heron is on the endangered species list and harming it would be a illegal offense. Although Raccoons are known for eating fish they will not venture into the pond if the water is deep. Make sure your fish have plenty of rocks and plants for hiding.

21. How much time is required to maintain my pond?
Proper design and construction are key in having a pond that requires little maintenance. Adding beneficial bacteria, monitoring of water quality, and cleaning the filter routinely is typically the extent of work required.