i have a wetdry, minipenguin, and have gone without the pads without noticing any effect for several months now. your main filtration will all be done in the tank with whatever live rock you have. it contains all the bacteria and organisms, big and small, that you need to keep your water clean. its only when you start adding chems and food, or overstocking the tank with fish, that your filtration will be tested. overfeeding will lead to excess nutrients in the tank that the life in your tank can not take care of in a quick manner and lead to problems of nitrates and phosphates in the water. overdoing chems can be toxic depending on the chem. i have generalized things but i think you get the point.
there are some benefits to the filter though. it is an extra space out of the tank that is easily controlled by you. you can put a sponge there to collect large debris floating around. carbon helps to absorb impurities in the water and with frequent changes can keep it crystal clear. you could add a phosphate absorbing media or double up on anything youve mentioned if you have the space. keep in mind all medias need to be changed on a frequent basis which can cost money. there again they are not mandatory to have so you could do without for whatever period you want. another use for the filter is water turn over. it greatly helps to oxygenate the water and helps to chrun up the surface of the tank. if placed in a strategic spot it can work in conjunction with your power heads to create water motion in the tank. you should almost think of it as a giant out of water power head. heck if you can fit it, you could stick a clip light on the filter and add some sand and a few small pieces of rock. just be carefull it doeson't get in the impeller.
there are so many out there
