Review on Fluval External Fish Tank Filter by Stephanie Love

This is my first external filter so I have no comparison. Moves a lot of water silently. However, be aware of two design issues. Every problem is a problem, but every problem is solvable if you are willing to work with it. First, some reviewers addressed the issue of microbubbles. I had this problem too. The microbubbles were enough to make the water look cloudy when you were just a few feet from the aquarium. After several conversations with CS, I found that there was nothing they could do to help. But I found the problem and the solution. When installing the top (motor) onto the canister, press firmly on all four sides BEFORE engaging the locking clips. Pay attention to the long sides where the top meets the canister and you'll see that if you don't press the top down firmly first, there will be a tiny (millimeter or less) crack. This crack is sufficient to allow air to enter the closed system. I thought the quirky clip system should have done the job but they don't pull securely on the top. Once this tiny tear is repaired, the microbubbles disappear. You may have to repot the top a few times to get it right. And lubricate the O-ring with silicone grease. Reducing the flow helps with this too, and since I have this on a 45 gallon tank, a reduced flow is usually fine. And I see a lot of complaints about the wheel cover falling off. I had this problem too. CS sent me a new wheel cover, but before it arrived I found this solution as well. Look carefully at the manual. The image shows you must press BOTH ends of the bodice to secure. With these covers (e.g. battery covers), all you usually have to do is press the tab. Not so with this one. After I reinstalled it, the lid snapped firmly into place by pressing firmly on both sides of the top. I think both problems are design flaws. I also think CS Fluval is only moderately useful. But if you understand these two issues, I think the filter works decently, but you may not get the amount of filtering you paid for. I have to say Fluval offered to replace this for me but they want the old block back before they ship the new one. The risk of my fish going days without a filter, shipping costs and hassles make this offer unattractive to me. I will use this until I get tired of solving the microbubble problem. At this point I'll probably replace it with a HOB filter.