A patio pond can bring a lot of interest and they are very easy to design because they are usually built using a water container of some sort.
It is always easier to design your patio pond when you have already found the ideal container for it. The size of the patio will govern the size of the container. For a simple container consider an old bath tub if the patio is big enough or a purpose-built pond form if it's not.
Decide what you will be having in your pond for plants and animals and then work out what equipment you will need to support them. At the very least you will need a submersible pump to filter and circulate the water and some rocks to vary the depth of the pond.
Having decided on the old bath for your pond, you can work out the best place to put it. While it is empty you can try various positions on the patio to see how it fits in. Since the pond will be a major feature you will also need to work out how to give people the opportunity to simply sit and look at it. Don’t forget that you will also need to have a power point available for the pump.
Preparing the Pond Container
Scrub the pond container with mild detergent and water and check for any greasiness or suspicious staining. If there are any rust spots where the enamel has been chipped, you can cover these with enamel paint when the tub is dry.
To make sure the drain hole is properly closed, coat the plug with a thin layer of silicone sealer before inserting it. Press the plug in as tightly as possible.
Decorate the Bottom
Cover the bottom of the tub with a mixture of sharp sand and gravel and if you have some suitable rocks place those into the tub so that they will create an interesting habitat for fish if you are going to have any. Fish like to be able to swim round things and shelter under them so you could position smaller rocks so that there are gaps for the fish to swim into.
Fill the Pond and Install the Pump
Fill the pond with water. Initially the water will probably be cloudy, but that will settle or be filtered out by the pump. Follow the manufacturer’s instructions to install the pump and filters
While you are waiting for the water to clear you could build a rough rock jacket against the outside of the tub to make it look less like a bath tub. You can either build this as dry or use mortar to fix the jacket in place.
Once the water is clear you can add fish and plants, and your pond will come alive.