So now you’ve decided how big and how deep you want your pond, you’ve decided if you want fish or not, and what kind–you need to decide how you want to add oxygen to your water. If you are raising fish–or even just plants, you definitely need to make sure they have access to oxygen in the water, which will be used up or eventually escape if it isn’t added regularly.

Another reason to make sure you are adding air to the water is because decaying debris in your pond can steal all of the air from the water, and add toxic gases that can kill plants and fish. The type of aeration needed depends on the size of your pond, but for something small like the one I have, not much is needed. For a larger pond, especially one deep enough for koi, you may need to take more drastic measures.

A pond bubbler is a small device that shoots a stream of water into the air. When the water falls back down, it brings oxygen with it, and mixes into the water below. This can be something as simple as the one pictured to the right, which is made by Pondmaster and run around $30, or something more incognito, like the rock bubbler pictured. These run upwards of $100 and come in various types of rock to fit your landscaping. A bubbler is also an option for keeping a portion of the water ice free in winter to allow an air exchange for any plants or fish you may overwinter there and will work in all but the coldest weather.

There are under-water pond aerators available for deeper water if you don’t want to have a spray of water above the surface. This one works great for really large ponds, but runs over a thousand dollars. It forces compressed air into the water just under the surface, but parallel to it–you may have seen it used in large ponds, as the green part floats on the top of the water.

Then there’s a smaller fountain to add interest to the middle of the pond. This one by Aquabelle has four different water patterns available and runs around $70. There are many similar set-ups available at big-box stores from the $30-range and on up, though they may be difficult to find at this time of year, or they may be on discount right now with the summer season coming to an end. I saw a pond kit for a complete pond with a small fountain for the middle that had been sold all summer at $100 go down to $40 a couple of weeks ago. My fingers itched to buy it because the price was so good, but I managed to control the urge–this may be one way for you to go, so check around if you are looking for something small.

Then, for those of us who just have to have a waterfall or some sort, you have the standard pond pump. It’s important to remember that not all pumps are created equal, and what you’ll need will vary depending on the amount of water you want to move and how far or high you want to move it. But I’ll cover that topic later this week.