dragonsong;4435055; said:Definitely upgrade to at least 800 to 1000gph, it's recommended that your turnover is at least 2x the size of the pond. If your not heating it definitely get a channel, they can take the cold weather and have personality too.
I would suggest more than that. I have 1000gph on my 70 gallon tank. That's 3 filters and I do not have a fish like an RTC