| 1. Is an ultraviolet light a filter? Yes, as far as the | | | | per hour pump. So you would need to get a UV |
| definition of filter goes. A filter is a device that | | | | light that is rated to handle 1,500 gallons per hour |
| removes unwanted material from liquid, gas, light | | | | passing through it. |
| or sound. Ultraviolet light removes harmful | | | | 5. Which is the best UV light to purchase? Do |
| bacteria such a pathogens from the water. In the | | | | your homework. Do not just compare the prices |
| case of algae or planktonic spores, the UV light | | | | of the unit. Compare warranties and replacement |
| would act more like a transformer than a filter. | | | | bulb prices. Find out the flow rates and the |
| The UV light transforms the live algae spores into | | | | amount of time that water is exposed to the UV |
| dead algae spores; it does not filter them out. | | | | light. What is the lamp life rating? Is it U.L. listed? Is |
| 2. Do I need an ultraviolet light in my pond? Some | | | | it made of UV resistant materials? Is the power |
| ponds need a UV light and some do not. If you | | | | supply easy to disconnect? Is the lamp easy to |
| have a small pond with a few guppies or | | | | remove? Does it have a lamp lens wiper so it can |
| mosquito fish, and it is 50% covered with | | | | be cleaned without taking the fixture apart? Is the |
| hyacinth, water lettuce, or lilies, and it is being | | | | transformer located on the cord and not on the |
| aerated by a fountain or waterfall, the answer is: | | | | UV light body? Does it come with unions for easy |
| No! If you have many fish, few plants, and a | | | | disconnection from the system for maintenance? |
| cheap bio-filter, yes, a UV light would help a great | | | | Buy a model that has the clear inspection cap so |
| deal. Most large ponds of 20,000 gallons or more | | | | you can see at a glance if the lamp is working. |
| tend to be more stable biologically and nature's | | | | 6. Where do I install the UV light in the system? |
| hydrogen cycle keeps everything in check. | | | | The UV light should be installed after the bio-filter. |
| 3. Does the UV light kill beneficial bacteria? You | | | | This way, you are running filtered water through |
| probably ask that question because some liner | | | | the fixture and it will stay clean longer. |
| pond guy told you, or you read it on his website, | | | | 7. How long should a bulb last? If you keep it clean |
| that it does. Well, it does not. Beneficial bacteria | | | | (once a week), it should last for 18 months. This |
| are not floating around with the algae spores and | | | | is all the more reason you should be willing to pay |
| pathogens. Aerobic and anaerobic bacteria, | | | | the extra $10 to $15 for the wiper model, |
| nitrobacter, and other bacteria are busy working | | | | because the labor would be too intensive if you |
| and doing what they do. They live on the surface | | | | had to take the fixture apart, remove the quartz |
| of things in the pond and in the rotting debris on | | | | lens, clean it, and then reinstall it every week. If |
| the bottom of the pond, breaking down nitrites | | | | you drop it or twist the cap on wrong and break |
| into nitrates and nitrogen, and breaking down | | | | it, it costs $60 to $80 for a new quartz lens. With |
| ammonium into ammonia gas. Ultraviolet light | | | | the wiper model you simply pull a plunger several |
| does, however, kill the microscopic animals such | | | | times and internal wiper acts as a squeegee to |
| as the rotifers and daphnia which each planktonic | | | | clean off the lens. If you do not clean the lens |
| algae ("pea soup" algae). However, the UV light is | | | | regularly, it will only last for a year, not 18 |
| taking care of those too, anyway. | | | | months. You can actually get two years out of |
| 4. What size should I get? Ultraviolet lights are | | | | your UV light if you turn it off during the winter |
| sized by watts and the number of watts you | | | | months when the water is cold and the algae are |
| need is determined by the size pond you have. | | | | dormant. |
| You should move the entire volume of the pond | | | | In conclusion I would like to suggest that you can |
| through the filter and UV light at least every | | | | never buy a UV light that is too big, but you can |
| three hours, and ideally every 1.5 hours. If you | | | | certainly purchase one that is too small! |
| have a 1000-gallon pond, you need a 1,500 gallon | | | | |