NICREW Slim Aquarium Filter, Quiet Fish Tank HOB Filters for up to 5 Gallon Aquariums, Adjustable Flow, 42 GPH, 3W

It's insanely hard to find a tiny HOB (hang on back) filter, especially one with flow control. I have a sponge filter in my 5.5 gallon, but I wanted a bit of flow without my sand being disturbed and this is absolutely perfect! I also love that it already comes with a tiny protector sponge on the intake (something I do with all my HOB filters for fish safety). It's even small enough to fit with my lid. Super quiet which is great because the tank its on is in my bird room. The price is fantastic in my opinion for what this is as well. I'll be ordering again for other small tanks in the future! Highly recommend

This affordable well built filter works well for nano tanks, I use this for my shrimp tank, it’s quite with minimal flow, I use filters from Sera, tetra, Seachem, Eheim.. and this filter is doing the job perfectly for the price.

Really love this filter! I bought it because I’d read somebody else claim it’s very quiet, and it is. You can hardly hear it running. It does a great job considering its size. I have the filter running on my 4 gal cube & it seems like the perfect amount of flow, but there’s a knob if you find it’s too much/little. I also love the built in motor style, because it feels like much less of a risk for spillage. I was impressed with the quality and thoughtfulness of this design, especially considering it’s only ~$10.

I don't normally write a bad product review. Normally, I just don't buy from the same company ever again. However, I think that this should be under the reviews so that people know. I ordered this item and at time of review, have had this hang on the back filter for 2-3 weeks or so. I woke up and checked and checked on my aquarium only to find water all over my hardwood floor and about 2 gallons of water missing from my tank. I look all over for the source as the water wasn't on the side of the tank or on the sides of the filter. I finally found a constant stream of water running down the electrical cord that runs the HOB filter. Luckily for me, I take precautions and there was no water near my plug. It was leaking where the cord meets the pump at the box of the filter. Buyer beware!! If you don't use drip cords or keep your plug at a higher location, this could be dangerous. If I was less competent this could have caused a fire. I would suggest this product to no one. It only got 1 star because I can't give 0 stars.

Bought 3 times found once leak but i still like it cause it’s easy to adjust the water flow

I love this filter. I have a small 4 gallon tank I use to keep my classroom fish during long breaks. It came with a bubbler type filter but it leaked and made a lot of noise. Not to mention the tank needed frequent water changes. This cleared my tank, is very quiet, and fits perfectly on the back of my small tank.

Have a UNS 45s shallow planted tank with 6 or so Medaka in it. Been looking for a filter mostly just for water circulation and oxygenation. I got a tetra whisper 4 at the recommendation of reddit and to their credit it is very quiet, I can't hear it sitting six or so feet away. However the biggest reason I didn't use a filter for a long time was because I was concerned about noise pollution causing stress in fish. Its an understudied topic specifically in aquarium fish but we do know that noise pollution in natural bodies of water does negatively impact fish in a number of different ways.So while I was very happy with how quiet the tetra whisper 4 was for me, when I put my ear ear up to the glass of the tank I could hear just how much noise it makes for the fish. Granted, I don't know if the fish care at all, but I was still looking out for a better option that was also still silent for me.Enter this filter. Even quieter from my perception compared to the tetra whisper 4, and the hang on back design means that the motor is outside of the water, and doesn't contribute nearly as much to the noise level inside the tank versus the Tetra whisper 4's submerged design. When I press my ear against my tank all I hear is a soft low hum, which I hope the fish appreciate. Anecdotally from what I've seen so far the fish are much more willing to spend extended time right up against the filter playing in the current.So if you want a quiet filter for yourself and maybe are concerned about noise pollution for your fish, consider getting this filter. Its cheap, and has a nice reservoir that if you don't want to use their filters, can fill with an alternative media like ceramic bio rings. The filter also has an adjustable flow rate which the tetra whisper 4 does not, and the intake element on this filter comes with a sponge to prevent an unlucky fish who wanders too close getting a fin ripped off.Anyway the Tetra Whisper 4 is still a quiet and a decent filter but for the money I would say this Nicrew slim filter beats it in literally every category.

I am giving it three stars because it was a very quiet filter with minimum water disturbance, which is great for a betta, however it was not appropriate for 5 gallons. after two days, my tank was a mess and had to remove it and put a more powerful filter on. I would think it would be OK in a 1 to 2 gallon aquarium but no more.