there is no wattage on the ultima 10,000 gallon, it is a flow through biological filter, you pump water through it and bacteria forms and eats away the nitrites and amonia and turrns them into less harmfull nitrates, that you get rid of with water changes, now everyone here is saying it is too much over kill, well listen to this, the manufacter suggests water flow for it maximun efficiency, im telling you that if you hook up a 200 gph pump, you are seriously under running the filter, but your not going to damage it, bacvteria will still build up in there and do its job, you dont have to use thgat big of a pump, im using a ultima 30,000 gallon filter on my 7500 gallons with a 10,000 gph pump, and it works great, my 4000 is crystal clear and my pool is crystal clear and so is my 1000 gal tank, all 3 running from that filter, with a 10,000 gph pump,
now you want to use the ultima 10,000 on your 500 gal tank, i say go ahead, that is 1/3 the filter im using, and 1/3 the pump would be a 3,300 gph pump, then you would be running the same flow as i do per gallon of water,
but your using alot smaller tank, so id go with a lowes or home depot pump running about 2,000 gph. trust me it will work fine, all your doing is not using your filter to its optimun, but later you can add other tanks and up the pump if you so want to,
now to the rest of you, hes talking about using the ultima 10,000 filter because he is getting it sooooo cheap, and it is full of media, so if you got it , id say use it, so what if your not using it to the fullest capacity,
you can fill a tub with medie and run a power head to it and let it flow back into a pond and it will fill with bacteria and become a filter, it is the same idea, there will be bacteria that builds up in there no mater what flow rate you run it at,
bigrich