I have two 5 pound bags of black sand that i just purchased a week ago ,the grain size is pretty big like the size of small pellet food or a little larger ,is this safe to use for my betta, the reason i am asking is i came across a site with betta care instructions and this is what it said about sand ,You really do not have to have a subsrtate but if you do have bettas are not able to have sand or any type of sand like substrate. (they are used to being able to eat things that look like pellets and I have indeed lost a betta who ate Eco Complete that was sand like) While a betta is pretty smart about a lot of things when it comes to food or anything about anything that looks like food they are pigs and there is not doubt about it. Please do take my word on this.Should i return the sand and get gravel instead,i really like the look of the black sand.