How do poor people filter their water?

Changing water with sump filter?

• I have a 55 gallon freshwater aquarium, and I am considering getting a sump filter. Since the filter add a considerable amount of water to my system, how much water should I change weekly? Hypothetically, let's assume my sump is 20 gallons. Should I change 25% of 55 gallons, or 25% of 75 gallons? And I have heard that you are supposed to take the water right out of the sump and leave the "show" aquarium alone. Do they really mean that you shouldn't vacuum the gravel in the aquarium? And why are people so obsessed with being able to choose their own filter media? There aren't that many types of different media, so that doesn't leave much room for customization. Why do people rant and rave about it, when in reality, there aren't many options.

• Answer:

  1) You change as much water as is needed to keep water quality up, there is no generic set amount, sump or no sump. Your water tests will tell you if you are doing enough, just right, or not enough water changes! 2) You can do water changes from the sump, it is one of the many benefits (you can do a water change without disrupting the fish). I do not ever use a gravel vac as I only have sand or soil tanks. I actually use my substrate to handle most my biological filtering in my tank (de nitrification). But you certainly can still do a gravel vac in the main tank if that is your method. Nobody says you HAVE to do a water change from the sump. 3) Sumps are more than just choosing media. They are 100% customizable. I use mine for media and plants, as well as to hide the heater, hide other filter add ons, as well as adding volume to the tank. I don't use too much for freshwater but find the sump-refugium to be priceless in saltwater. There are tons of different types of filter set ups, media, and add ons....UV sterilizer, chemical and mechanical media, many reactors (phosphate, nitrate, CO2, etc), fluidized bed filter add ons, skimmers for saltwater, planted refugiums, biomedia (bioballs, ceramic rings, biofloss....), etc, etc, etc. In reality there is a million ways to customize your sump no matter the application! Also you can custom plumb the tank do do auto top offs to refill evaporated water or to change the water with a flip of a valve, etc. The sump is super nice because all this stuff is hidden under the stand and not hanging all over your display. In my freshwater tanks I tend to prefer the canister filter and saltwater I love teh sumps or hang on back refugiums. I only use sumps on my freshwater tanks over 150 gallons as they do make things easier.