Or as the great Martin Moe Jr. would say, "why rent a truck to return a library book." Nearly all tables provided by aquarium retailers and manufacturers are very optimistic and quite skewed about the capabilities of their equipment. They also do not tell of the decline of a UV's capability with out the water being crystal clear, nor due they talk about the lights loss of effectiveness with age. And as can be seen, they usually just provide tables that are based on a lights ability to kill phytoplankton in fresh water ponds. Then they throw out a few rough guidelines for salt water or salt water parasites that are nor substantiated with research/test data. The reefers in Germany have been using UV lights a lot longer than the US reefers. I would be more inclined to follow the Reefers advice form Germany than some inadequate tables supplied buy a retailer. A very large portion of the advances in Reefing are due to the German reefers and German manufacturers. We generally just take their equipment and build it out of cheaper materials of lesser quality and call it American made, or we contract the manufacturing out to the Chinese and call it an American product.
Small pumps are cheap to run, I would recommend a separate loop for the UV light utilizing a small pump and not a large flow pump shared with a sump return system. The large wattage light is larger than is needed to be effective.
As for its effectiveness at killing the Ich parasite. You have only about 48 hours that the Ich tomites are free swimming and therefore capable of being in the water stream to be pumped through a UV light. Whether or not that happens is more dependant on adequate circulation within the tank more than killing power within the lights UV waves. It does not take extreme intensities of UV lighting to kill the free swimming tomites but it is very hard to ever get the tomites into the water stream in order to get them to the UV light. They are typically hatched in or on the substrate and very quickly attach to a host upon hatching. Healthy fish with a good mucus layer do not normally have parasite attachment problems. Please also consider that circulation heavy enough to keep parasites in suspension in the water will also keep most plankton and pods in the water system also flowing through the killing UV lights. UV lights are considered by many as best for treatment of bacterial and algae blooms, or prevention of same, but not for parasite preventive measures. Unless your running a bare bottom tank where tomites can not hide in the substrate, and therefore will be kept in circulation within the water.
Quote:
Originally Posted by hma  The longer the water remains in the UVC, the greater is the effect, the more bacteria and germs are killed. The faster the water the UVC passes the LESS germs and bacteria are killed.
A Quite simple, easy to understand and logical circumstance in my view.
In contrast to Marine Depot I do not sell a UVC as expensive as possible. However, I have tested at the University of Frankfurt with some students different UVC with different flow rates, the result stands in MY Chart and is based EXCLUSIVELY on sea water. We have really counted out bacteria and germs in a dedicated quantity of water for every tested UVC after 24 hours of running time. The results are to be read up in the Chart.
Of course would be also killed bacteria and germs with a quicker flow rate and higher wattage of the UVC but not so effective and with substantially higher costs. (power consumption, purchase price; spare parts)
In Germany we have a saying: " Why with doves to throw at sparrows "
My recommendation for a 360 gal. Aquarium is 18 watts UVC, used in a separate circulation with a small pump (240 gph) 24/7 in your sump.
BTW ... I am use a 11 Watt 24/7 for my 225 gal FO. |