What do you mean specifically by not a good enough job? Do you mean the frogs are looking ill? cloudy water? or nitrate/nitrites too high? ACFs are not much of a bioload and I would think that filter would easily do the job. Is the tank cycled? Are you feeding appropriately so that there isn't extra food? I commend you for thinking of upgrading. However, a larger filter may cause too much current for the frogs. Their kinda loungers and you want them to be able to chill out. They aren't from raging rivers or anything and a 10g doesn't give any room to hide from a strong filter current. Maybe you just need to stabilize some other factors instead? I added plants to my 10g betta tank that has an ADF. All I did was choose lower light plants and put in some compact fluorescents that screw into a regular 10g hood. Added a few fert tabs to the substrate and a few drops of ferts every week or so. The tank looks great and everyone is happy and healthy. The frog really likes the plants and I can't say enough about how much healthier of an ecosystem you create for your them.
BTW, your 5g is super over-loaded
Too bad you have ACFs instead of ADFs. You could get a cheap 20g off CL and put them all together and they would all be better off space-wise.