filter?

Question
I am planning on purchasing a 2.5 gallon rectangular tank and a betta fish. Does a tank this size need a filter? And how much water should be changed?

Answer
Hi
A filter is always a good idea as it takes some of the stress out of tank maintenance. Without a filter you need to do 50%water change every second day. With a filter I would recomend a 50% w/c every 10 days.
The filter you need is made by Red Sea - called a Nano Filter - it's rated for up to 3 gallons, and has all 3 components (mech, chemical, bio) - should run you around $15.
When doing a water change always use a dechlor / water conditioner. Good luck
Shawn