FILTER FOR A SMALL TANK - reccommendations?

I have a 5.5 G tank with a betta. Currently doing 2 - 3 50 - 60 % PWCs per day to keep NH3 down below .25 No trace of NitrItes yet but only been about a week, (and I unknowingly rinsed the filter with tap water the other day when a bunch of junk came out of it on startup)

I am new at this, but finally got a small gravel vac to keep the poop down.

Tank and Tap PH is about 8.2 / Tap H20 is low, almost zero... Using API Complete Fresh Water Test Kit.

All the above said, I currently us a Hega Elite Mini Filter, cycles around 58 GPH with aeration on lowest setting so as not to freak out the betta

I have been eyeballing the Duetto DJ 50 (I like the adjustable flow setting that seem it actually works, and price as funds are very tight).

However I keep reading about filtration systems, and am confused over so called "bio" filters that look like regular foam and even considering possibly a sponge filter. However, it seems difficult to find a small tank filter on a small investment budget with an adjustable flow rate that ranges for say 20 - 45 or 50 gph....

Am I unrealistic in my expectations or does someone out there have a product they would reccommend.... I know it sounds silly but i am not wild about running a separate air hose either, as the tank sits on the kitchen counter....

Thanks

 

Go with the Duetto if you don't wish to use the air. They are good filters.