I have aqua clear filters in both of my tanks that have a bettas in.
The current isn't too strong, but they are both in tanks bigger than 5.5g [20 & 10] So they have enough room to avoid the flow.
But since you have a small tank I would recommend a sponge filter or one of these maybe :
http://www.petco.com/product/12147/P...FishFC_Filters
What kind of lid do you have?
I tried looking online to find a hood/light combo to show you for a 5.5 but I couldn't find one.
If you can find one tho to fit that size tank I would get one.
The size upgrade is great!! :) :)
But I would remove maybe 1 or 2 plants, IMO.
And make sure none of them are pointy enough to tear his beautiful fins.
One thing I got that both my bettas love, is the Betta Log.
He is a beauty tho :) :) :)
I bet he's enjoying having some more space.
What kind of siphon did you get??
Siphoning a tank that small might be hard.