I have been a fish hobbiest for about 35 years and curtently I have a 90 gallon oscar tank, a 20 gallon tropical community tank, a 40 gallon fancy goldfish tank, and a turtle/goldfish pond. Let me say you are lucky your goldfish has lasted as long as it has. Unfortunately with the care you described it will only work for the short term (in the goldfish life this may even be 8-10 years) then stress, disease or both will take its toll. Never use soap or any cleaners to fully clean a fish tank. Any soap residue left behind is deadly to fish. Also cleaning the tank as you do kills the benificial bacteria in tank. This bacteria is needed since it consumes waste and reduces amonia build up. My guess is your tank never looks crystal clear but kind of clowdy. This is called “new tank syndrome”. What this is is the benificial bacteria trying to establish itself in the tank. One thing you did not mention is if you had a filter. If you don’t have one I suggest strongly you get one. As for the water changes buy what is called a “gravel vac”. This will clean all the crud out of the gravel and syphon out the water. I suggest as well as most aquarium experts, doing a 25% water change once a week and rince the filter media in the siphoned water. Once a month replace the filter media. You should leave the goldfish in the tank when doing this as it will keep the fishes stress level down. If you refuse to get a filter do 5-10% water changes every 2-3 days. I hope this has been helpful, but if you do not want to listen and take better care of the goldfish the eventual loss will be yours to deal with.
Fish Tank Filter: Aquarium & Fish Tank Filters | Petco
Betta fish really should have a tank at least 5 gallons large, with a filter and heater. a 5 gallon tank is only 13 dollars and is much easier to maintain. An aqeon quietflow 10 filter is about 15 dollars and a heater is around 12, but if your room temp is high enough you do not need a heater. Keeping a fish in a tank that small is like keeping a dog in a closet it's whole life.
Filter for a 1 Gallon - Aquarium Advice - Aquarium Forum Community
This little filter would be a great upgrade for one of those aquarium kits that comes with the 1, 2, or 3- gallon tank plus the hood and the air-pump filter. People love those tanks for Betta fish, but they have their drawbacks.
I'm thinking about getting a filter for my 1 gallon aquarium