Grech CBG-500 5W UV Sterilizer Hang-On Back Filter, 10-30 gallon/132 GPH

The UV feature is amazing when setting up a new tank or if you get an algae bloom. I set up a 10 gallon tank for some guppies and platies and within a week the water clouded up due to an algae bloom (typical for a new tank). I turned on the UV light and within days it was crystal clear. Once it cleared up, I turned off the UV lamp and the water has stayed perfect.I also like the filter design. You don't need to purchase expensive same-brand cassettes/filters or anything. You can use your own media and build up the filter however you like. I'm using ceramic bio rings, crushed coral in a mesh bag, and the foam that came with it. The water is crystal clear and all water parameters are exactly where I want them.Lastly, but not the least important thing I love about this filter is that it re-primes itself after a power outage! I have tried several other small HOBs that couldn't and they burned themselves out due to lack of water at the impeller. As long as this filter stays in the tank and water levels are where they should be, it has restarted EVERY SINGLE TIME we've had a power outage. One outage was 4 hours long and this was humming along when I got home.Other notables:- it's quiet- easy to set up- easy to clean- flow is adjustable- it has a surface skimmer that is adjustable and works great

Been looking for a while for a UV solution that would work for a small 10g tank. Everything else I found was standalone bulbs that would go in a canister or inline system which didn’t make too much sense for something this small. Filter is quiet enough, great flow rate and the surface skimmer is a nice addition. Super easy setup and worked great right out of the box. Cleared the water up completely within a couple days with no water changes. Love how the filter media is setup as well. Very easy to swap/clean media without having to pull everything out.

Overnight it had already cleared up a little of my algae it’s very quiet. I love the fact that you can put your own bio media instead of filters which are a waste of money. I buy bio media in bulk which makes this a good money saver. It seems effective overnight and will upload a new photo if it clears my algae. *update* it works great but the skimmer doesn’t really work the way a skimmer should work. It doesn’t spin and skim nicely the way others do. This one kind of just struggles to spin.

Hi, I purchased this filter (already opened) to resolve an algae bloom in my 10-gallon planted aquarium, which I've had for over a month. I received it in perfect condition. I installed it today and had no issues getting it to work. I'll let you know later if the filter successfully cleared the green water. However, compared to my Aqueon Quietflow 10, which I was using, this filter is quite noisy. I think this is because the inlet tube and the telescope are separate pieces, causing them to rattle when in use, while the Aqueon Quietflow 10 is a single piece. Good luck!Note: Two days of using it, and the filter has cleaned my green water, just as advertised. The initial rattle has also decreased. Very happy with the product; now I give it five stars.

I've never heard of this company before but they make a filter that will give Marineland and Aqueon a run for their money in the HOB market. Three-stage filtration, a UV sterilizer with an on/off switch, and a surface skimmer all in one package with the added ability to control both filter flow and skimmer suction independently make this thing a workhorse for any tank. My only complaints are that the compartments that make up the media column are small (but easily discarded if you need more space) and that the pump itself only dumps water on top of the column, which limits water flow through the bottom half of your filtration system. Still, for the price it's an unbeatable all-in-one filtration solution.EDIT as of 9/26/18: pump burned out after less than a month of use.

I've never heard of the Grech brand in aqaurium filters before but this unit really impresses me.I've used a lot of small HOB filters and this one seems to be the best of all the major brands. It has a strong powerful motor for its size and creates a nice current at its output. I use this filter on my 15G vertical tank. Its a perfect fit in size.Its loaded with all the features you could want:1. NO, yes NO proprietary removable filters! Saves on $$$.2. Uses a sponge filter and 2 filter boxes you can load with chemical and biological filtration media of your choice. Comes with both an activated charcoal filter bag as well as ceramic media balls. But you can choose your favorite media to use since they just fit into individual boxes.3. Provides for mechanical/chemical/biological filtration for maximum water clarity.4. Also includes a surface skimmer to suck up any oil/whatnot slick that may form on the water surface from food/chemicals you may use5. Includes a 5W UV filter to kill parasites and algae that can infect and cloud the tank water! This is a big plus!6. The unit is heavy and substantial in build with a strong motor for high water flow in small tanks.7. Water flow and surface skimmer are fully adjustable and the UV lamp can be manually turned on/off as needed.8. The entire filter mediums are in an easily removable (use 2 fingers) stack for cleaning and replacement without shutting the unit off or making a mess.Pretty much everything you want in a small HOB filter is here and seems to work very well. Overall, highly recommended.Finally the seller provided very fast shipping on this item. It came at least 4 days sooner than expected and in great condition!