SunSunHw303B 370GPH Pro Canister Filter Kit with 9-watt UV Sterilizer

I’ve been a fish tank enthusiast for 30+ years. In the past I owned many different canister filters including some well known pricey brands and I would have to say this one is by far the best. I have absolutely no negative things to say only positive. It’s easy to maintain it keeps the water crystal clear and the best thing about this affordable efficient filter is how ultra and I mean ultra quiet it is. I bought it over a year ago and it runs and sounds the same as when it was new. The first night it did make a little bit of noise and I thought I would have to return it but when I woke up the next day I had to check to see if it was still running because it was so silent. I definitely recommend purchasing one for yourself you will be happy.

The Sunsun Hw 303B is great. Just finished setup in my marine tank. Read the reviews and tips. Mostly about using silicone lubricant (do not use Vaseline it will dry out the seals and crack them use silicone food grade lubricant only) on all the seals and purchased some of that as well. Turns out the company must be listening because all the seals were already lubed sufficiently from the box. Setup went very well with no leaks and it’s very quiet. I had modifications I had to do and the parts they supplied for the send and return were just what I needed with some careful thought. Be careful if you need these parts the cheaper ones may not come with them. They are less expensive because they don’t include the various nozzles, hoses and fittings.The only glitch I ran into was a big one if I hadn’t had some experience with these filters previously. The pictures I have supplied show the indicator for the uv light. This is what shows you the light is on or off. It’s just a plexiglass shaft that goes from the light chamber inside to the top of the unit. 1st pic shows it (circled in red) on the inside. It should be flush to the bottom of that area. 2nd pic shows it topside(again flush to the top surface). This piece was not in the proper position and would not allow the inside glass cover for the UV light to properly seal at the bottom or as in pic 3 the lock to properly engage fully. It took some doing to get it into its proper position but it finally popped in and allowed the glass cover to seat properly and the lock (shown in pic 3 circled in yellow) to fully engage over the flange of the cover. Had I not seen this it could have sent water into the light chamber and outside of the unit, frying the light and possibly shorting out the entire thing. Maybe worse since water and electricity don’t have a history of working well together. 4th pic is the final setup. I put a bin under to catch water in case of leakage as some suggested but so far it isn’t needed. It’s dry as a bone.Short of that I’d definitely recommend this unit for a small tank but take your time with setup, think things through and watch a few YouTube videos to avoid the pitfalls.Update as of 1/17/2024 :Still running well and zero leak issues. UV still functioning as well. Has developed some noise. It’s definitely noticeable but tolerable. Tried all the fixes recommended for canister filters on Google and YouTube to no avail. May try replacement of the impeller. Otherwise it’s performed diligently.

Overall I am happy with this filter, but I am new to canister filters and it’s only been a week running. I however am not new to keeping an aquarium and have used sump systems and hang on back filters on and off for over 30 years. I ended up purchasing the sun sun after reading many articles on best filters, the sun sun customer reviews, and watching YouTube videos on maintaining them. My experience so far is positive.One of the zippered mesh bags holding the ceramic rings was torn, but that’s an easy fix with needle and thread- the bag is not really needed anyway. Everything else was in great condition.The instructions are short and you have to read into them, but all in all they are okay if you have good problem solving skills and an imagination.One thing I read about often is leaking of hoses due to the plastic fittings provided with the filter, and compatibility issues with in line heaters. I purchased the datoo inline heater (I think it’s a sun sun one with a different name- it monitors in Fahrenheit instead of Celsius). I had zero compatibility issues and have experienced no leaks. It’s almost unbelievable because so many experienced aquarists are reporting leaks and the need for metal clamps. I’ve had none of these issues. Been holding my breath and set up everything in buckets to catch the water if the hoses should fail, but all is dry.I did have to cut about 3-4 inches off the end of the intake tube attachment because it was too long for the height of my aquarium. Two extensions to this tube are provided, so no worries if I were to take off too much. Otherwise, no other issues.Note: not all of the Sun Sun canisters have a UV light and come with filter media. I purchased the 303B and it came with both.Overall 4 star rating is because it’s only been a week running.Update: let me remind you that this is my first ever canister filter. Its been a couple of months now and no leaks or even hints of a leak. As far as I can tell, there is no need to go out and buy metal hose clamps (which I did based on reviews and ended wasting money). Easy to clean- no problems removing and replacing any of the filter baskets. For those of you who have never used a canister filter I was worried about how I was going to remove the hoses without all the water siphoning away-there is a lever that seals the hoses off and releases them from the lid of the canister. The water remains inline and I don't have to worry about the heater burning out (although I did unplug it and wait a bit before my maintenance of the canister).I have amended my rating to five stars. Great price, great performance, easy to maintain.

The pump is working great-- a tremendous improvement over my Fluval U3 that I had inside my tank. It cleans easily, canister parts are of good quality and good construction. The parts that come with it that go in the tank for intake and return are pretty cheap and don't seem like the correct size. Nor are they air-tight-- air is getting into the intake setup, which accumulates in the canister and makes it operate louder. Plan on building your own intake and returns using hardware store parts. It works great that way.Documentation stinks! English documentations appears to have been written by someone with limited education in English and in technical writing. Impossible to assemble with the instructions provided. Thank God for YouTube and the people that post how-to videos. I couldn't have done it without them. There is nothing in the tiny booklet about how to clean and service the canister, impeller, etc.