I am about to buy a sun sun filter which has a 9wat UV filter in it, the filter is 2000L/PH and my tank is 500 liters. Would this amount of UV light really make a difference in my tank? I not buying the filter especially because of the UV filter its just an added bonus. This filter will be replacing my jebo 1500L/PH which has stared to reduce in flow, its 3 yrs old. The sun sun filter will be running with the 2000L/PH trickle filter that is part of my AquaGrand tank by AquaOne.