Sunsun Sun HW-704B 525 GPH 5-Stage External Canister Filter with 9W Uv Sterilizer

After reading some reviews on Amazon and watching a few YouTube videos on the SunSun HW-704(B), I decided to purchase one for my 30 gallon tank. The unit was shipped out quickly and arrived in good condition. It seems that SunSun must have also quality checked the canister for leakage since the filter sponge was slightly moist. I am pretty happy with it and bought another one for a new 50 gallon tank a few months later.Although I only use it once or twice a week, it's nice there is a UV sterilizer light to sanitize the water. Some people seem to have issues with the light damaging the plastic trays, but this seems to be a problem only if the light is turned on all the time. I didn't see this as a defect, but took it as something to keep in mind since the heat from any light placed next to plastic can cause it to degrade over time. There is also a small indicator light on the top of the canister to let me know that it is working.The build on this seems pretty good. The outside of the canister is sturdy and it fits between the legs of my 29 and 40 gallon metal Imagitarium tank stands from Petco. The green hose can be fitted onto the inlet and outlet by softening the hose - just dip each end into hot boiled water for a couple of seconds before slipping it over one of the canister's nozzles. Once it cools, the opening will contract to form a nice tight seal. I have not had any issues with leakage using this method.Note that there is a round orange sticker at the bottom of the inside of the canister. Use this as a reference when placing the baskets back inside. Make sure that the orange sticker aligns with the holes of the baskets. This is to ensure that the light is properly situated so that the UV light will work. This is a small but thoughtful touch on the part of the manufacturer.The unit is pretty quiet. If you are used to the sound coming from a hang-on-the-back filter, you will probably be happy with the reduction of sound from this canister filter depending on how you set up the return pipe. The pipe on my tank is set up to release the water back into the tank below water level to minimize splashing sounds.When I had a questions about the canister, I reached out to the seller who promptly responded and helped me. I am very happy with my purchase and the customer service and would not hesitate to buy the filter from this seller again.

After a month or more of comparing canister filters I decided to with the SunSun 704B. I have normally used Marineland and have been happy with their products. I decided for $50 cheaper to go with the SunSun. I will say the instructions are not the best but if you take your time and apply common sense you will get through it. The design is pretty standard for canister filters. I was surprised how much media this filter holds. I ordered extra floss and pads (which I didn't need to do) there are plenty included with the filter. I'm not sure about 525 gph but it definitely moves a good amount of water. The filter is plastic and all trays are as well but it seems fairly sturdy and should last for several years. The trays can only be lined up one way because of the way the top fits and the UV light slots have to line up. Makes it a little easy to remember each time. I can't think of any major issues I have with the filter and would definitely recommend giving it a try. The price is great ( actually a couple $$ cheaper) than when I purchased. Shipping was quick and setup was not bad.

These are priced like disposables for a reason. One was DOA the other Died after 6 months, third still running fine.I bought two of these to replace two Rena Filstars I have been running on two large tanks for 9 years. I too was drawn in by the low cost and reported capacity. Of the first two I bought, one leaked from the start. The other was fine. I tried putting a little silicone grease on the seals to see if that would stop the leaking but it did not so it had to be returned.The second was working fine for the first 3 months but, following a power outage I noticed that it also began leaking if the pump wasn't running. This was a huge problem for me because I live in a heavy lightning area (Tampa Bay area) so there are frequent power outages. By this time the replacement for the first filter had arrived and has been running fine for the duration, although I am still not as confident leaving the house for several days.Meanwhile, the second filter was getting worse. All my fish started dying off. But the water was clear and everything looked fine. Eventually every fish died except one trooper of a greenback. A couple blennies, starfish and hermit crabs also survived, but everything else, about 12 fish, died. I decided something bad had gotten in the water and I would have to clean the tank. When I touched the tank I got what I thought was a static electricity shock. But then I touched the water and got a shock from that. Through process of elimination I learned it was, of course, my cheap filter. I got a shock while standing on a dry carpet floor. I wonder what would have happened if my tank had leaked more and soaked the carpet and THEN I touched the water. Luckily I only populate my tank with interesting fish from the bay so the cost was minimal, although I did feel some remorse about slowly electrocuting my fish to death.Now this puts me in a jam. because even though this was sold by American seller and eligible for Amazon prime the company is Chinese. Therefor, after the first month all problems must be resolved through the Chinese company. This means to be repaired or replaced will likely take up to a month there and a month back. Even if they sent a replacement before receiving my return it will be at least a month. This means I would need to find another filter to hold me over for that month. Then I would have to hope that the FOURTH filter doesn't crap out like two of the first three did (not a safe bet).I am 51 years old and have had aquariums and terrariums most of my life. I have never had any filters fail at the ridiculous rate that these do. In fact, I can never even remember a filter failing. I have only bought new filters after several years when it feels like they just aren't strong enough anymore, or for larger tanks. These filters only had three trays filled when I used them. The first two had gradually finer filter pads and the third was a layer of biohome. The fourth was empty. They were cleaned every two months. There was nothing impeding the flow to cause such a failure.they are cheap because they are cheaply made and unreliable. Even if they start off working fine they can start to leak or have system failures even under perfectly normal circumstances and with no warning (except a lowering water level). And, as stated earlier, you will never feel completely confident that your tank won't drain if you leave the house for several days. My tank has two large tanks in the cabinet underneath in case of leaks. By the time I caught the second filters leak the water was an inch from the top of the drainage tank. If I did not have that tank I would have had about 30 gallons of water on the floor and if I was a way I could have had another 40. That is too much risk and future worry to save about 50 bucks.It was worth a shot for me but let me save you the hassle. Go with something more reliable. The lack of problems and much greater peace of mind are well worth the extra money. I will try to return the second unit for a refund and find something I won't have to worry about so much.Update: NO CUSTOMER SERVICE RESPONSE! I sent an email to the company, Sunsun, on the same day I posted my review. I sent it to their complaints department, their North America Manager and their company manager as listed on their website. I sent a follow up email every day. Still no response. I will update if they ever respond.

If you do not have noise issues, this unit is really brilliant, very well made. The pump rattles and is too noisy for my bedroom aquarium.