Like it, nice and lowtech. You seem to be like me put a more filtration than you need lol. My 5.5 gallon is the only tank I've "underfiltered" to help I just added more of my Ehiem bioballs into the filter, filter probably is good for that size of tank. If anyones wondering its the Azoo Mignon filter, I recommend it as I has adjustable flow and is nice and compact.
Do you have the Aquaclear turned all the way down?
15 Gallon NPT
1g no tech bowl in the making