The Fluval U1 Internal filter has an adjustable flow to ensure the filter meets the needs for different aquarium environments, minimum output creates a gentle flow perfect for planted aquariums whilst the maximum output increases circulation and oxygenation. About the smallest filter I think I've experienced (excluding simple box filters of old) is the Aquaclear Mini (now called the Aquaclear 20) I'm currently running on our quarantine tank. I find 3 (not always present but potenially there) noise problems with this filter: first, the impeller and shaft are not as high quality as you'd find in an expensive filter and can get noisy over the years; second, its an HOB, so there's the built-in waterfall noise that you can only escape right after water change time; thirdly, there's the little plastic top cover, which can hum and which of course you could choose not to use or to modify I suppose. Of course, the simple rectangular media box gives maximum flexibility, which is what makes all these ACs be contenders in the first place.

I decided on the Fluval U1 as this was ideal for a 48L tank and it had the built in venturi valve that I wanted on a new filter for aeration. Large pallet items like aquariums are deemed delivered successfully with no damage once the the driver has left the property. If a report of damage is submitted after the driver has left we may be unable to assist with replacements. We recommend refusing a damaged delivery, this is the fastest resolution.

The X-Men would be happy to see these evolutionary mutations, and so am I. The inclusion of features that add to the design can only be a good thing, and I hope to see this line of thinking stretched to encompass more products. Evolution and not revolution indeed!

The adjustable 3-way flow control feature lets you position the water flow output to meet your specific needs. The Top Output setting provides maximum circulation and oxygenation, the Integrated Spray Bar setting provides a gentle, even flow for planted aquariums, and the Bottom Output setting is for deepwater agitation.

Fluval U1 Internal Filter

So what’s changed? The first ‘tweak’ appears minor, but is actually essential. A tag on the front of the filters, as soon as you extract them from their boxes, shows you how to remove the impeller and give it a clean. If the pictures are confusing, then you can always scan the QR code instead, and watch a video about it. Accessing the impeller for maintenance is a doddle. position horizontally for shallow tanks, larger tanks with low water levels, or to create a decorative waterfall feature Anyway I am now making use of my other power head as a bubble machine but that is for another thread on how I converted my power head into a bubble machine with no need at all for a Venturi Valve of any kind and one that has a proper flow rate.