Having an ultra violet pond filter will give you a much better chance at keeping your pond water clear. When used in conjunction with your regular pond filter, it’s more than likely that you will have nice clear pond water.
The way it works is this. As water in your pond passes through the ultra violet pond filter, the UV light inside of the tube kills the algae. As the algae dies, it begins to clump together. Now your regular pond filter goes into action and traps these dead algae.
Without one of these ultra violet pond filters it will be difficult to keep your water clear, and on sunny warm days you will get algae blooms like you wouldn’t believe, which in turn will make your water pea soup green.
You can get a couple different kinds. They make a submersible kind and an external one. Personally, I think it’s better to have a submersible UV light, just for the simple reason that they’re out of sight. They are durable and should last you for years, although you may have to replace the light bulb after so many hours of use. In a nutshell, you really don’t want to be without an ultra violet pond filter.