Reddit mentions of Jardin Aquarium Efficient Economy Corner in Tank Filters

The tetra whisper filters for small tanks are powered by an air pump. You could run one of those.

You could also do a sponge filter or something like this

You could also look into a USB powered pump and use it to rig up some sort of filtration system.

You could try this pump out, looks great!

https://www.amazon.com/gp/product/B00511P8CS/ref=ox_sc_act_title_5?smid=A39G1UAOFK1OOE&psc=1

Be sure to also pick up the air pump;

https://www.amazon.com/Tetra-Whisper-Easy-Aquariums-Non-UL/dp/B0009YJ4N6/ref=pd_bxgy_199_img_2?_encoding=UTF8&pd_rd_i=B0009YJ4N6&pd_rd_r=QYZDEBFVK4HDGMKK5HE2&pd_rd_w=wYWS0&pd_rd_wg=hoOdK&psc=1&refRID=QYZDEBFVK4HDGMKK5HE2&dpID=51PhS3RJRSL&preST=_SY300_QL70_&dpSrc=detail

and tubing

https://www.amazon.com/dp/B01L4BV1E2/ref=twister_B01L4BV1VK?_encoding=UTF8&psc=1

OH ok! How about those... Box filters? It works same as a sponge filter (powered by air pump) but you can put different kinds of filter media such as those porous ceramic filter pieces and since those are heavier, it can keep the box filter from floating around. Something like this:

https://www.amazon.com/Jardin-Aquarium-Efficient-Economy-Filters/dp/B00511P8CS/

Bubbler can be found here btw: https://www.amazon.com/gp/product/B00511P8CS/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

I'm very happy with my sponge filter! Here's my set-up:

• Filter = Jardin Economy Corner In-tank Filter
  
• Pump = JW Pet Fusion 200
  
• Airline tubing = Penn Plax Standard 8-ft
  
• Check valve = Lee's 2-way Plastic Valve
  

Definitely try online/Amazon, I find cheaper items there usually. If your tank doesn't come with a filter, this is a cheap one and good for bettas because of the low flow.

For now I have it slightly pointed up so it is creating a slight current to the top surface. The flow of water is going directly to the heater already dispersing the heat.
I think I might put the heater directly on top up my sponge filter so I have movement constantly. I also saw [this filter] (https://www.amazon.com/dp/B00511P8CS/ref=psdc_2975472011_t2_B00HSCB9GC) that I may wanna try. Anyone have thoughts on this vs a regular sponge filter?

Most likely not (working as well). And there are ones that for the price of getting the materials to put into the container, and the container itself... well... you could have just gotten one of known good materials:

(side note) your betta may LOATHE the surface disturbance from the bubbling... I seem to be getting far better responses from the hagen/fluval/aquaclear 20 series for the smaller tanks... has adjustable flow, and far quieter than an air pump.

option 1:
http://www.amazon.com/Jardin-Aquarium-Efficient-Economy-Filters/dp/B00511P8CS/ref=sr_1_3?ie=UTF8&qid=1462470473&sr=8-3&keywords=bubble+filter

option 2: http://www.amazon.com/PENN-PLAX-SAM-Penn-plax-Bubbler/dp/B0002AQ2LY/ref=sr_1_4?ie=UTF8&qid=1462470473&sr=8-4&keywords=bubble+filter

http://www.amazon.com/XY-380-Aquarium-Biochemical-Sponge-Filter/dp/B0051XIN78/ref=sr_1_1?ie=UTF8&qid=1462470473&sr=8-1&keywords=bubble+filter

HOB filter: http://www.drsfostersmith.com/product/prod_display.cfm?c=3578+3579+3608+3610&pcatid=3610&r=2

I switched to this corner filter and put Seachem matrix at the bottom instead of the ceramic rings for extra filtration since I have a snail and they're poop machines. This sponge filter is also a good option if you only have a betta since it takes up less space i n the tank. A lot of others on this sub have used it and seen good results from what I've read.