AQUATICLIFE 115 Mini Internal Protein Skimmer/Filter for Saltwater Aquariums, 30 Gallon, Perfect for Small, Nano Tanks

This is definitely by far, my favorite nano/mini skimmer. I have a 20 gal saltwater tank, with three clowns, two hermit crabs, a snail, and one small hawaiian sand anemone. I use Instant Ocean Reef Crystals, as well as supplements. About 15lbs of live rock, and a 3 inch thick live sandbed. This fits in the corner of my tank quite nicely and doesn't disturb/bother anyone or anything. As a matter of fact, my clowns are always hanging around it. There are, however (as with all skimmers i believe), some drawbacks to this one, but lots of pros as well.Pros: After a month or so of running this, micro bubbles are nonexistent. Not too sure why everyone is complaining much about this, i have absolutely no micro bubbles in my tank. And no, i have not added any sponge or filter floss to it.Works brilliantly; I empty/clean the collection cup every two days or so. By then, its collected a large amount of scum, and not just watery kind. Its a good (I like to call it good because its out of the tank~) thick green/brown color, and ready for disposal. Yeah, sometimes it doesn't collect as much, (end up with wet scum) but it usually does its job well.Easy to set up; Pretty much just plug and play here.Hardly needs adjusting after its breaking in. I just adjust it perhaps every week/two weeks, if need be.Easy to take apart; Just remove the two pieces that firmly keeps this together and you're in.Pretty good price for what it does. I'll be starting another tank soon, a 15 gal this time, and this is definitely my first choice. If only it didn't make that gurgling sound, it would be pretty perfect.Cons:Its loud. Not too loud, but its annoying. I did look up that youtube video, and modified this. However, it still makes that gurgling sound, and I'm not sure why. I believe water might still be going in the valve somehow, i'll get around to fixing it someday.Adjustment knob is small and difficult to turn. Thankfully, I've found a sweet spot and can just twist it a little to adjust it to the level i need it to be. Not too big of a deal for me.All in all, this is definitely a great skimmer, and I really do recommend it to anyone with a 25 gal and under tank. If only they would get rid of that sound...

I have been using this in my 29 gallon bow front for about 3 weeks. It is awesome. It does spew a lot of micro bubbles at first, give it some time. After about 8 hours there was a noticeable decrease in the amount of bubble and now there is an acceptable level. It does take up quite a bit of room and my glass cover no longer fits. I will need to get the back glass cut to compensate for it. I guess it is notable that I would prefer to trim the glass cover than to remove the skimmer. It did not take long to set it up, maybe 45 minutes, but I was playing with the settings to see if I could get the bubbles to stop. Don't bother, they won't stop completely. Maybe it is me, but I have never had a protein skimmer that did not introduce micro bubbles into an aquarium. I have it set to allow the foam to rise about half way up the collection cup. Occasionally the foam spills over the top into the cup. I am getting about 3/4 of a retention container a day of skim-mate. My water is crystal clear. This skimmer is fairly quiet. The aquarium is in our living room and the noise is not very noticeable.Some things I don't like are:1. It is very difficult to get the retention cup to seat on the unit while it is operating. This is a silly design. It does not need to fit as tightly as it does.I have thought about taking a knife to both parts to trim some of the plastic down but so far it hasn't bothered me enough to warrant the time.2. The unit interferes with the tank's glass cover. If they had placed the collection cup and air intake at the back of the unit I think the tank cover would fit better. At least I would not lose as much of the glass cover.3. The hang-off-the-back bracket does not allow me to raise the unit high enough to meet the water line requirements of the skimmer. I tried using a block of wood but in the end decided to lower the water level of the tank. This seemed to be the best compromise. Not sure why they did such a poor design of the bracket. They ended the ratcheting section too early. It needs to extend all the way to the top of the bracket to accommodate a greater range of adjustment.All things consider, you can't go wrong with this. It is inexpensive and effective.