that tank is okay for the jar and bare minimum for the silver..rtc will not fit for life..your current tank is way too small but the fishes do look good..get your new tank as soon as possible mate. dont add any more fishes .
I'm sure someone will come on here telling you your way undersized tank is OK as long as you do your best and give the fish lots of love. Me...well lets just say my opinions on your tank and fish would differ from that.