skimmer selection help

[Myka]

I don't understand the theory behind not needing a skimmer for a small tank. If someone can provide a decent explanation for that I'm all ears.

IMO, a skimmer is just as useful on a 250g tank as on a 5g tank. It performs the same job with the same results. The Tunze Nano Skimmer is a bit on the expensive side, but is nice and small, and would be a great performer on a tank your size. If you want something cheaper, maybe try the Bubble Magus which I have heard a lot about, but I couldn't recommend on my own accord as I really know nothing about it.