Upgrade Green Spotter Puffer tank filtration?

[Lizknife]

I have a 29 gal GSP tank that I've had for about four years. I have two hob 70 gal Hagen filters and do weekly 50% water changes. I'd like to upgrade my filtration system. Does anyone have any recommendations? I keep the salinity around 1.009.

Thanks,
Liz

 

[Rbishop]

I'd add a small to medium canister and remove one of the HOBs..such as a Marineland C-220...