This may be a stupid question but I'm going to ask anyway as I feel I might be getting bad info from my uncle. My uncle said I don't need to purchase a vacuum/siphon "just stir up 1/3 the substrate during my weekly water changes then move onto the next 1/3 the following week and so on". Does this sound like bad advice? Currently I have a 10 gallon w/ smooth gravel, 4 false Julio Cory & 1 male Betta. Tank 2: 20 gallon long w/ pool filter sand, 5 female Betta's heavily fake planted. Both tanks cycled prior to adding fish. Thanks Kris