Should I use a flexible liner or a preformed pond? Liners are usually easier to work with and easier to install. If you choose a preformed pond make sure it is deep enough to meet your needs.
How deep does a pond need to be? It should be 18" to 36" deep for water gardens and 3' deep or more for koi. Deeper ponds may need to be fenced for safety. If you are only adding plants, shallower ponds are safer, easier to work in, and better for the plants.
How do I figure how big my liner needs to be? The length of your liner needs to be the length of your hole at its longest point added to the depth of your hole at its deepest point added to the depth of your hole at its deepest point (again) plus 2 more feet ( to go out over the surface a foot on each end). The width of your liner needs to be the width of your hole at its widest point added to the depth of your hole at its deepest point added to the depth of your hole at its deepest point (again) plus 2 more feet (to go out over the surface a foot on each side). A hole that is 14' long by 10' wide by 2' deep needs a liner that is 20' long and 16' wide.
How do I get rid of green water? Create a balanced system in your pond. Plants, filters, bacteria, and a thin layer of gravel in the bottom of your pond will help. Don't put too many fish for your pond and don't feed them excessively.
How do I get rid of string algae? String algae helps to keep your pond clear. It also provides food for your fish. If it becomes excessive, you can remove part of it with your hands or leaf rake. Don't try to get rid of it completely.
Do I need to add fish? Not for balance, but a few can add interest to your pond. They are easy to care for.
How many fish can I have in a pond? You can have up to one inch of fish for every one square foot of surface area of your pond. This means in a 10' x 10' pond, which is 100 sq. ft. you can have 100 inches of fish. This can be 20 5" fish or 10 10" fish. Remember your fish will grow, so don't put in too many at the start.
What kind of filter should I use? If you only use one, use a biological filter. They only need to be cleaned if the water is being blocked from moving through them. Some can be mounted outside the pond.
How big a pump do I need for a waterfall? Measure how wide your waterfall is at the start of the falls. You should have 1000 GPH (Gallons Per Hour) is pump capacity for every foot of width of the falls.
How many gallons of water does my pond hold? For square or rectangular ponds, multiply the average length in feet by the average width in feet by the average depth in inches by 5 and divide by 8. A 10' x 15' pond averaging 16" deep holds 1500 gallons (10x15x16x5÷8). For circular or oval ponds, multiply the full length in feet by the full width in feet by the average depth in inches divided by 2. A 10' x 13' oval pond averaging 21" deep holds 1365 gallons (10x12x21÷2).
