I run two FX5's on a 210g and its just right. I am setting up a 300g and I plan on using the two FX5's along with two FX6's so four total. So one for every 75 gallons for me
cool i plan to switch out the sunsun 304b with a eheim 2262 soon.I do the same on a 180, plus a trickle sump with 10 gallons of bio balls and still feel it is inadequate. I am pretty well stocked
LMAO .two so you can have one running while cleaning the other