Question
How do frogs get into tub ponds that are above ground? Do tub ponds need filtration?

Answer
Frogs are good at hopping and can jump into above ground ponds.  Tub ponds don't have to have filtration but they will look cleaner if they do.  I have tub ponds with and without filtration.  My page on tub ponds is at http://www.fishpondinfo.com/tubpond.htm

Good luck!
Robyn