hello i am looking to start a piranha tank. I have a 45 gallon tank to start them off in would that be ok to house 6 baby 1 inch piranha? also ive seen many people do sand for their piranha where do you buy the sand is it a special type? ive looked at petstores around where i live and i cant find any? anyway what would be the best piranha to buy caribi red bellys? and also i will have an eheim pro 2 canister filter and two double bio wheels for filtration