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.

I have had aquariums for 40 years and this is a non compensated review. Just received item today and I set it up in 5 minutes and had it running in a 10 gallon quarantine tank which I intentionally allowed to develope algea so that I can evaluate the uv portion of this filter which if I determine to work well will eventually be installed in a 4 gallon nano planted tank which is currently being filtered by fluval c2 filter. The fluval c2 is a wonderful filter but has 2 shortcomings that I hope this grech 500 can compensate for. First the amount of dust/ oil film on the surface which the c2 filter is not equipped to deal with. And second because I run high intensity led and co2 , the subsequent algea, again that the c2 struggles with in a nano tank. So that's the logic behind trying this grech 500, it has a adjustible skimmer installed in the intake tube and a 5 watt uv sterilizer bulb pre filtering water. So far the grech is working well but,,,, Here are my concerns/ suggestions for improvement. First the fine filter pad seems a little undersized, second the on off switch for the uv light is located on the lower rear of the filter housing( should be on one side or other not rear)can be difficult to see/operate if the aquarium is place backed up to a wall like most aquariums on display are. And third no discription for approximate lifetime of uv bulb or where to obtain replacement bulbs.Also would prefer that the uv bulb had a separate power cord so that itcould b e plugged into a separate timer. So far all other aspects of of the grech appear to be a clone or clone like of aquaclear filters and appear to work as well or better. I will up date this post in 3 months after it has really been thoroughly utilized.***update 01/19/18 filter has been run for 4 months and I am so impressed with its performance that I swapped it out onto my nano 4 gallon planted tank replacing the fluval c2 filter, I only run the uv light for approximately 1 hour a week and it keeps the the tank crystal clear even with co2 and lots of bright led light.. very impressed very y quiet also.

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!