If you are near a petco the petco power filter 20 is a pretty good find..Adjustable flow..The input tube is also adjustable so it can fit in a 5 gallon tank..it's registered for 5-20..I have one and I love it..Took out the pad and put marineland bonded filter media and cut it to fit the filter and now has twice the amount of area for beneficial bacteria.
Good luck with your cycle!! And I hope you find Pudge! :) I'm going to start to cycle my 3.5 gallon with a sponge filter. My pH is pretty low though. :/ It's going to be hard with that 6.5 pH and the small tank size. I just noticed that you live in NYC!! A couple of my relatives live there. They probably don't even though what a Betta is. lol
You can get mesh at hobby lobby or walmart usually, just ask some one where it is... or do you already have some? i could even mail you some..... although i may have to fold it or something. but its very possible. i buy it all the time here,i could mail you some of mine...
"Sometime" next week is the trip to Walmart, so I will most likely be getting a 5 gallon there, and then hopefully right to Petsmart to get Pudge! Petsmart is right next to my Walmart so I hope my mom will let me <3
I COULD wait until I return to my LPS to get a betta when I'm in college, but all they have are Veil tails. I'm hoping for a something other than that for my next fish to try some variety :)
Attached is the mesh I bought, and the second image is the one divider I made (It's not cut yet. I removed it soon after)