HI I have kept my goldfish in a bare bottom tub with a hob filter on the bottom. As I know how much waste can get caught in the substrate and also being a tub it would be a night mare to vacuum. Is there a substrate that I could use that would not need vacuuming and I could just run my hand through for example to get rid of most of the debrI caught in it . Also I don’t mind keeping it bare bottom if no substrate would work. Thanks.