So I have a 20 gallon tank right now and thinking about upgrading to either a 29 gallon or a 20 long. Currently I have a stock of 1 pleco, 4 yoyo loaches, 5 guppies, and 2 rando's that my daughter got and I don't know the species. I really only wanna upgrade cause my babies (the loaches) seem like they aren't getting enough space. So if I upgrade to a 29 inch could I add a rainbow shark to this stock and maybe a dwarf gourami or would it be too crowded? Also if I change and use the same filter the cycle should be uninterrupted right?