Since the tank isn't planted, easiest fix is to turn the lights off. Algae can't grow without light. Second suggestion is learn how the biological filter works in your tank and how to care for it. Sounds like you have too much light (for a non-planted tank) and the ammonia problems often associated with an immature tank.
I have 2 sponge filters in my 55gal planted with this filter and I never have issues
I bought Hel-X instead of the K1 in this vid but both work great and makes for a great conversation piece
anyway the point of my post is that I havent touched it in aprox 8 months and it still works great I alternate every 2 weeks cleaning my sponge filters every 2 weeks and that's it.
I do 2 20% water changes a week with heavy feeding and never have issues
when I do clean filters I use tank water not tap water