For more info on hardness and pH, see this article: <a href="http://www.tropicalfishkeeping.com/f...quarium-73276/">http://www.tropicalfishkeeping.com/f...quarium-73276/</a> Quote: and on another note, the tank i wanted to get was a 40 breeder but my father said it was too deep (front to back). the other option is a 38 gallon which has dimensions 36.5x13.5x19.8. i believe these are outside dimensions. would this affect me much at all? in terms of fish/substrate/ro