As I’m researching reef tanks, I keep seeing sumps and I’m not completely sure what they are. Is It just another type of filter? Do I need more advanced filtration for a 5 gallon reef tank than a HOB? I was planning on using a seachem tidal 35 since it says it has a built in surface skimmer but now I’m not sure if that’s gonna be enough filtration since I’ve seen people use sumps for pico tanks. My other concern is that the media basket is gonna be too small since I have it on my 20 gallons freshwater aquarium and it’s pretty tight but I don’t know if the next size up would fit on my 5 gallon tank. Plus I don’t want it to be an eye sore when I actually fill up the tank since it’s cube shaped with no designated spot to hide equipment. Also, for filtering I was going to use the bio bag and sponge that it comes with along with some carbon and filter floss. Is there any other and/or better filter media I should use instead? 🤔 thanks!