Labrat is a blue damsel. A fish, cheap, kind of like a lab rat. Get it lol, labrat. I am checking for arsenic but I dont thik I have to worry. he is still swimming. no change in ph, phosphates or calcium.
As for the limesand comes in a 90lb bag. or by the 5gal pail from a stone yard. look in the phone book under stone. call and ask for limesand.