I currently have pea gravel(pictured) would this be ok for corys. I know alot of people recommend sand. It is a possibility that I could change to sand( thinking black sand so fish stand out more) but I have no experience using sand as a substrate. I like to syphon my gravel with every water change to keep the water as clean as it can be. How easy is sand to syphon/keep clean and will shrimp and nerite snail be ok with sand.... also I have been looking at the African dwarf frogs they look interesting any thoughs on the frogs. Thanks.