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Aqua One Aquastyle 850 Carbon 4C

Aqua One AquaStyle 850 Carbon 4C is replacement filter media for the AquaStyle 850 Only.

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Product Description

The Aqua one 4c carbon and polymer wool cartridge is one of our best selling products for a good reason - it works exactly as it should, trapping fish waste and purifying aquarium water for 4 to 6 weeks after which it gets thrown away and replaced. What could be simpler?

Aquarium Maintenance Made Easy...
The 4c cartridge itself is however quite a clever little thing designed with complex aims and objectives in mind. The polymer wool top layer is carefully manufactured to be a specific thickness - dense enough to trap a month's worth of solids yet not impede water flow. The polymer layer is also carefully bonded to the carbon tray, in such a way as provide support and prevent sagging when it gets dirty.

The carbon tray does indeed hold the carbon granules which are an essential and very purifying but can also be messy if left to roll around. Water always attempts to take the easiest path through a filter so the carbon tray not only neatly contains the carbon but also ensures that water is evenly distributed throughout the cartridge making the most efficient use of the available filter area. Water then leaves the cartridge in an even manner meaning that the black sponge layer and bio-noodles are also utilised in an even, efficient manner.

Beneficial Bacteria
The Aqua One 4c carbon and wool cartridges are not designed to grow the beneficial, nitrifying bacteria so often sought after by the fish keeper. Rather the 4c is around to stop harmful solids and excess chemical waste reaching the foam and Bio-Noodle layers which will grow a nice thick layer of good bacteria.

4c cartridges don't always last the full six weeks in between changes and it's worth checking on their performance once per week. Just lift the filter lid and peer in. If water is 'pooling' on the surface polymer wool layer rather than passing straight through, the cartridge is blocked and should be changed. Don't attempt to wash the cartridge under the tap, it has been used up - change it.

Change every six weeks
While the 4c carbon and wool cartridge needs changing every six weeks, the foam and Bio-Noodle layers are much longer lasting. However there is a limit to how long even these well designed items last. So, change a few Bio Noodles every month to stop them all becoming clogged up at once and change the foam/sponge layer yearly at least. In between, the sponge layer may be rinsed in a little aquarium water, which is then thrown away of course.


Aquacadabra acts as credit broker/intermediary and not as a lender.

Klarna's credit products are provided by Klarna Bank AB, which is authorised and regulated by the Swedish Financial Services Authority, with limited supervision by the Financial Conduct Authority. More information can be found here.

Newpay finance options are provided through Deko’s platform by NewDay. P.D. Aquatics Ltd, t/a Aquacadabra is an Introducer Appointed Representative of Pay4Later Ltd, t/a Deko, which is authorised and regulated by the Financial Conduct Authority (ref no 728646) and is a credit broker, not a lender. NewDay Ltd is authorised and regulated by the Financial Conduct Authority (ref no 690292) and is authorised by the Financial Conduct Authority under the Payment Services Regulations 2017 for the provision of payment services (ref no 555318). More information can be found by clicking the newpay option above, or in the Newpay FAQs.

Delivery & Returns

We really want you to be happy with the product that you've received. If however, when the goods arrive they're not what you want, then no problem - we have a 60 day no quibble return guarantee. Just let us know that you're going to return the item(s) by contacting us (stating your Order Number) and complete the returns packing slip that will have been included with your delivery. This will help us to quickly identify the item that you have returned (unopened and unused) - and we'll put a refund through for you.


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