For 350 liters, a Rena XP3 would do very nicely as would a Marineland C-360. Both have more than adquate flows and lots of space for the filter media of your choice. I have an XP3 that is 4 years old and doing quite nicely to serve my 120 gallon tank. I have the smaller C-220 on a 45 gallon and it is also running trouble free. Both filters are silent in use, which is very important to me.