I went to buy salt mix today and I came across a wet/dry filter…it had an overflow box that looked like the u-tube thing we talked about to break the siphon, and a skimmer that sat down in it. I’m not sure what kind of media was in it..they wanted $260.00 for it at the fish store. What is the difference between a wet/dry and a sump? I can see that it is sealed and kind of looks like a cross between a canister and sump it didn’t take up much more room than a 10g tank. Can anyone give me pros and cons on this type of filter system? Thanks in advance.