Interpet Internal Aquarium Fish Tank PF3 Power Filter, Cleans Water, for Coldwater & Tropical Aquariums Up to 126 Litre

I bought a PF1 for my 55l tank and while it was okay I had to clean my tank much more often than before. I’ve upgraded to a PF3 and it’s much better. Maybe go one bigger than you think you’ll need.Design-wise these are much easier to maintain than some brands I’ve had in the past.

Purchased for my 60l tank and i have to say easy to clean and very powerfulll as well

Really quite a powerful little filter, seems to work well but is a bit noisy. I have to keep it right on the water level to reduce noise to still allow for water oxygenation

I've been keeping tropical fish for more than 30 years and owned numerous internal and external filters. I bought this one for my mother in law, who had a small tank (about 30 litres) and where the one that came with the tank was a bit too rubbish to use.The first thing I would say with internal filters of this size is that they are intended for pretty small tanks. For this filter I would say a 50 litre tank would be the absolute max. External filters are better but there aren't really any in the market for the smaller tanks, hence getting an internal is the way forward.Internal filters provide lots of water flow but don't always have very much filtration capacity. As with every internal and external filter, the media provided is very much optimised for ease of cleaning and replacing, rather than for filtration capability. As I say this is true of every brand I've ever used.The filter contains a small plastic compartment in which there is some ceramic media for biological filtration. The remaining space is filled with a sponge to perform mechanical filtration and a carbon infused sponge to provide chemical filtration. These are attached to a plastic holder which easily slides in and out of the filter for cleaning.If you are keeping a planted aquarium then I would dispense with the carbon sponge because activated carbon removes the minerals the plants use to grow. The carbon sponge only lasts a month or so and needs replacing around that time anyway.The few ceramic media in the filter is nowhere near enough to provide good breakdown of ammonia into nitrites and from nitrites to nitrates. It's also not a great quality media with not very much surface area for the aerobic bacteria that perform this job to grow. I replaced this media with Biohome media from UKfilterPro as this has a far greater surface area and contains beneficial minerals which are added in the production process.As for the mechanical filtration sponge, it does a decent job and some aerobic bacteria can grow on it, but I chose to replace the entire media with coarse, medium and fine pads and then added some more Biohome in the main body of the filter. For this I removed the plastic holder and cut the media to shape to fit in. Coarse at bottom, medium next, fine on top of that and then the biological media.The end result of these changes is that water quality is far better but doing this means having to buy new media. Generic filter sponges are very cheap but really good quality media for your aerobic bacteria is a bit more expensive. I bought the sponges for a couple of £s each and I'll do 3 or 4 filters for that. I bought £10 worth of Biohome and that will do about 4 filters of this size too. So not expensive and nothing I've put in needs throwing away and replacing, just cleaning.It's not really any harder to clean once you've cut the new sponges down to size either.For anyone experiencing noise from their filter, this is almost certainly going to be air trapped in the system. This means water is not flowing seamlessly from the inlet at the bottom to the impellor in the top of the filter head. This can mean your filter is blocked with large amounts of detritus, or the rubber inlet membrane in the bottom of the filter is blocked or even damaged. This membrane should be removed and cleaned every few months. It is breaks it can be replaced but running the filter without it will result in inconsistent flow and air pockets.Unless you have very, very good filtration, water changes are a necessity. It requires a good source of anaerobic bacteria to break down nitrates in the water and in a small internal filter this is never going to happen. There is too much oxygen for the growth of good bacteria that flourish in environments which lack oxygen. I would recommend 10% water change every 7 days but more if the tank is more populated.Nitrates are what causes algae, so if you are getting a lot of it, you will need to do slightly bigger water changes. It might also mean you are overfeeding the fish, there are too many fish in the tank and you are leaving the light on too long. Waste food and fish waste become nitrogen based waste and that will lead to high nitrates one way or another.I also own a PF4 in a 11o litre tank and that runs well, (with the same media changes). A tank of that size could use an external filter where there will be room for a lot more media.

Easier to clean than old filter

Excellent little filter and a very reasonable price.

This is thebest pump/filter I have use up to date well worth the little bit extra very efficient and easy to clean with different air flow speeds when on hi is rather loud but fine when you put it at water levele with plastic shield

I bought the PF3 Sep 22 and am on my 3rd replacement impeller. The white rod that joins the impeller to the magnetic body is brittle and prone to snapping. I suspect the poor quality impeller cannot cope with the strength of the filter which when it does work is very good at what it does. Buy with a view there's running costs associated with maintaining it either by replacing pads and impeller as required. Its not quiet and the noise is clearly audible around the entire front room.