When I first got my tank I asked for suggestions on filter. Everyone was very helpful. I ended up ordering both the Azoo and the Fluval. I gotta say the Azoo is the better filter. It is quieter, cleans faster, and easy to work with. Because the tank I got had a lid that did not have an opening for an external filter, we did cut out a space for it and it fits great!
I absolutely hated the Fluval for my small tank (3.5 g) as it took up too much room and I certainly did not want to take it out every time I wanted to change/clean the medium. It also did not seem to keep the water very clear. I do have a 10g tank that I might set up and use the Fluval with (it is rated up to 15g) so it might be easier to deal with in a larger tank. It is also pretty quite and I did like the adjustable water flow (which the Azoo also has).
I bought extra foam pads and a bag of medium for both filters. The ones that come with the Azoo are kinda cheap, but I cut them an made a layer on the bottom of the filter and put a bag of medium on the top. I also then put a fine pad in between the medium/pad and the outflow to help filter out any particles that might have gotten through.
There was a great youtube video that helped me set up the Azoo as it is not well documented. I was not quite sure on how to set up the bag of medium. I think the guy is called asianfishguy. The medium video was from another poster, dont remember the name. But if you search for it, it should come up.
I also got a small under the grave heater that was not highly recommended (ordered before I got that post). It is also working great. Keeps the temp pretty consistent at 82 degrees. I also got a little digital thermometer to go with the heater. It is pretty spot on as I have checked with a inferred thermometer to compare.
Finally, and I am sure I will get flamed for this to no end, my tank was divided with Romeo on one side and Juliet on the other. Almost every day I had to get one of them because they kept jumping over the divider. So I just took the darn thing out and the two have been living together for about 2 weeks now with no problem. No fin nipping, fighting, and just the occasional small chase like any other fish. I have added more plants and a rock hideout since I removed the divider so Juliet could hid if she wanted to. But they usually just hang out together in peace. As I have learned with my skinny pigs, not all act the way that is the norm. I certainly will still keep an eye on them as I do not want anything to happen, but so far so good. They seem happier together. BTW - I am not trying to mate them. There has not been any nest building. Do fish go into 'season'?
I will post photos of the new tank/filter setup. I just love my little fish and they are great to watch.