hey hows its goin man.
glad to see some1 getting back into the hobby of fish keeping.
for cool fish a 30 gallon tank will limit you. but i guess that also depends on what u concider cool.
u could go with a serrasalmus species prianha. but to be honest piranhas are a varry boring fish.
dragon gobys are a nice fish but kinda hard to find around here these days. and can be sometimes hard to care for in a newly setup tank.
the blue dolphins u are talkin about i think are the african cichlid species. these for the most part have to be kept in species only tank. ie only african cichlids species.
if african cichlids are what u are looking to get into. that is what i specialize in rite now. i have tons of baby colbalt blue zebras and yellow tail aceii. the aceii are a varry nice colourfull fish that do well in schools of 5 or more.
the colbat zebras are a bright poweder blue. bolh varry nice fish.
or if different is what u are lookin for. i have rocket gar fish for sale aswell. well i have one left instock rite now he is about 5 inch long and will eat live feeders. or flakes. (he can also clean up all them tetra u said u have there) lol
i mostly deal in either group african cichlids. or varry rare and exotic fish. another fish i have for sale is a blue phanton pleco. aka alge eater. he is a varry rare exotic pelco form lima peru.
or if nothing i said seems apealing to you send me a email
reamfcanada@gmail.com and i can help u decide on what type of fish u would like to keep in the tank. and how many. as i said the 30 gallon limits you. unless its a 36 inch wide tank then u have abit more leeway with what u can keep. fish like space. and aggressive fish need lots of space. lol
if there is anyting u are looking for in particular let me know i can usually track down just about any type of fish from anywheres in the world.
have a nice day
im not in bussiness yet. technically so there is still no tax!!.