Good filter for 40g overstocked tank

[Sexytang]

I have a 40g that’s heavily stocked don’t want to spend a lot of money but want a good filter non sump that will keep it good and clean. And I don’t run a skimmer

 

[Philly Reefer]

What is your expectations for that new filter?
What are you trying to lower?
Nitrate? Phosphate?

I think your options are canister filter(nitrate factory, but it will polish your water) or HOB refugium