wut uyre doing will not work...sadly enought...6 relines...650 gallons...ummm equal big nono...suggeted size for adualt snakeheads is 8 feet by 24 inches height doesnt matter...well over 1 foot...i have mine in a 48-18 inch tank...umm...hes 10 inches...and he just ate his friend the 7 inch snakehead...they do not accept tank mates...and ure plan wont work...they will eventually kill each other...because 2 will pair up...if u got males and females..and kill the rest of them..so ull probably have 2 left in a few months...when is this pond supposed to be built...they get close to 2 feet after a year...and ure tanks are too small to house one 2 foot fish let alone six...well anyways good luck with wut ure doing...