Setting Up and Cleaning a Juwel Aquarium

Juwel aquariums are widely regarded as some of the best aquariums available. They come in a variety of elegant styles, suitable for both beginners and experienced hobbyists alike. All of the aquariums featured in the Juwel collection are of extremely high-performance, utilising Juwel’s ground-breaking aquarium filtration systems, quality aquarium heaters and a brilliant LED lighting system.

Here we discuss how to set up your Juwel aquarium and tank, how to keep it clean and running effectively. If you have any more questions regarding the Juwel range, don’t hesitate to get in touch and chat with us about it.


How to set up a Juwel Aquarium

Juwel aquariums come fully loaded with all of the equipment you require to get your aquarium up and running. This excludes decorative materials such as gravels and ornaments. Here we will discuss details of how you set your new Juwel tank up.



In order to get your Juwel aquarium going firstly, you will need to erect the cabinet (if using one). In order to do this, you should follow the instructions provided, ensuring all structural details are followed carefully to ensure safety.



Juwel aquariums all come with an integrated, boxed-in filtration system which contains all of the vital components of the aquarium, such as: the biological and mechanical media, (Ecoflow) pump and (Aquaheat) heater. This is a huge selling point of Juwel aquariums and a main reason as to why we love them! You really do get a lot of bang for your buck.

All of the previously mentioned equipment will need installing correctly. To begin, you should:

  • Unpack the media sponges and insert them in the correct order (detailed within the aquarium instruction manual) into the media compartment.
  • Once this has been completed, the heater should then be slid into place and hooked on to the designated clips. 
  • After this, the pump should be inserted at the top of the filtration compartment, ensuring a good seal is made with the designated O-rings.

Once everything is comfortably in place and you’re happy that the above steps have been followed carefully, place the filter box lid on. If you are in doubt about any of these steps, please refer to the Juwel aquarium instructions provided.


Once the above has been correctly completed, the light should be fitted into the lid if not already done – this will depend on the model of aquarium you have purchased, and the lid should be installed on top of the glass work. When placing the lid on, the relevant electrical wires should be passed neatly through the back of the lid, ready to be plugged in. 



Everything should now be in place, so you can proceed with basic decoration and filling the aquarium with water. Firstly, you should select an appropriate substrate and place this carefully in the bottom of the aquarium. Please note, some substrates may need washing thoroughly prior to putting in the aquarium.

You should aim for a depth of around 2cm – 5cm. Any deeper than this can turn the substrate into a dirt/bad bacterial trap which can be difficult to clean and cause issues with the aquarium later down the line. You can then begin to fill out the aquarium using ornaments and rocks, ensuring that the ornaments make good contact with the glass aquarium base. The reason behind this is to stop any ornaments falling over should the substrate be moved by yourself or the fish.


Adding water

Once you are happy with the basic look of the aquarium, you can begin to fill with water. In order to not disturb the substrate, this should be done slowly or by directing the water flow on to something (such as an overturned tupperware box) in order to distribute the water gently. Once the aquarium is full, you can then plug in all electrical appliances. This is a great time to check everything over, ensuring it is working correctly.

Your Juwel aquarium should now be up and running, though you need to wait for it to get up to temperature before adding any fish. Please note, if you are using chlorinated tap-water it is important that you add a solution to remove any chlorine and heavy metals prior to adding any live stock. We like the Fluval AquaPlus Water Conditioner Solution for this.


How to clean a Juwel Aquarium

When cleaning a Juwel aquarium, we recommend taking the following steps:

1) Invest in a low-cost kitchen sponge used exclusively in the aquarium. You should use this to wipe down the glass sides of the aquarium, dislodging any algae which has adhered to the glass on a weekly basis. We would recommend supplementing this with a magnetic algae cleaner for daily use, to save your arm getting wet. We like these algae magnet products:


2) Once the algae has been removed from the glass using the sponge, this will normally settle in your substrate therefore, it is now time to do a substrate clean. In order to do this, you should first invest in a suitable gravel cleaning tool. We recommend:


When doing a gravel clean, place the head of the gravel cleaner in the water and start a siphon, with the wastewater going into a bucket nearby. You should use the head of the tool to poke around in the substrate, removing any solids along with around 10-15% of the aquarium water. DO NOT DISPOSE OF THIS WATER.


3) The next step in washing your aquarium filtration involves the water previously removed from the aquarium during the gravel clean. Turn the filter/pump off and remove the filter sponges and/or media from the Juwel filtration box, and add them to the bucket of soiled aquarium water. It is imperative to only ever use aquarium water for this step – NEVER FRESH TAP WATER.

The biological element of the filtration is very delicate and the chlorine and heavy metals present in tap water kills off the good bacterial colonies. This will lead to poor quality which results in detrimental fish health. You should spend some time massaging the sponges to clean off any fish waste/solids. You are not looking for the sponges to be immaculate; instead, you are looking for them to be ‘quite’ clean.

Once completed, return the filter media back in the correct order to the Juwel aquarium filtration box and replace the lid, preparing the system to be turned back on. Now, dispose of the soiled aquarium water.


4) Ornaments, rocks and other removable decorative parts of the aquarium can be cleaned on an ad-hoc basis (as and when they’re required). This can actually be done in aquarium water, tap water or even the dishwasher providing they’re not porous. The idea here is to remove any algae or grime stuck to them. Toothbrushes and sponges are great tools for getting into any hard-to-reach areas.


When do I change Juwel filter pads?

In terms of changing Juwel filter sponges, the manufacturer will stipulate how often these should be changed. In our experience however, filter media sponges should only ever be changed when they are irreversibly damaged. Over time, the structure of the sponges will decay, will begin to deform and will not return to their original shape. This is the point where we believe that the sponges should be changed.

The sponges play an incredibly important role in the aquarium by harbouring good bacteria – replacing the sponges will rid you of the good bacteria which can negatively impact the aquarium. If filter sponges do require changing, it is a good idea to not replace all of them at the same time. Instead, change a single sponge and wait several weeks before changing the next. This will allow bacterial colonies to transfer from sponge to sponge.

At the top of the filter, sponges will exist a filter floss layer known as a bioPad. This is NOT a biological filtration sponge and instead is purely mechanical, i.e. designed to remove solid particles from the water therefore, improving clarity. These should be changed much more frequently than the sponges; every 1-4 weeks depending on stocking levels. They will be visibly full of fish waste impeding water flow through the filter and pump - you will know when they require changing.



What types of Juwel Aquariums are there?

All of Juwels’ large aquarium range come with the option of a matching cabinet, in a variety of colours (Black, White, Dark Wood and Light Wood). The range consists of the Lido, the Vision, the Rio and the Trigon, all of which are available in several sizes to suit all rooms.

Primo- At the more traditional/basic end of the spectrum, there are the Primo aquariums available in a variety of sizes (70L and 110L). These may be simple however, they are phenomenal value and look great. These are typically available without a cabinet.

Lido- This is a taller, slimmer, square shaped aquarium ideal for an alcove. This aquarium is ideal for larger fish which require a little more overall swimming height, such as Discus. It is incredibly sleek and looks fantastic up against a wall or in an alcove.

Vision- With its elegant curves, the Vision has a curved front from left to right providing an unparalleled viewing experience. The visions’ cabinet matches the curvature of the glass, providing a seamless look which looks fantastic in a corner, in an alcove or simply against a wall.

Rio- This is the most contemporary of the Juwel aquariums. The oversized glasswork sits on a slightly smaller cabinet allowing the edges to overhang, giving it a modern, fresh appearance. Again, this looks phenomenal in a corner, in an alcove or simply against a wall.

Trigon- The Trigon is a large triangular shaped aquarium designed exclusively to go in the corner of a room. The overall footprint is big, so your fish will have plenty of room to swim.

In all instances, Juwel aquariums can be adapted to cold water, tropical and marine. Regardless of the inhabitants, they always look great!


How many fish can you have in a Juwel Aquarium?

There is not a straightforward answer to this question and it will depend on a number of factors, but mainly the size of your Juwel aquarium and the species you’re planning on keeping is how you decide.

As an example, a Juwel Rio 450 will be able to house more fish than a Primo 70. However, it is also important to consider the overall size of a species i.e. a Primo 70 could house 50 neon tetras, but a Rio 450 could only house 5 fully grown Oscars.

The best advice here is to do your research before committing to purchasing a species. Think:

  • How big do they grow?
  • How messy are they? (cold water fish such as fancy goldfish are very messy)
  • Do they live well in communities?
  • What size communities do they do best in?

 The best way of answering this question is by undertaking regular water quality tests. Slow and steady wins the race with fish keeping. You will have the greatest levels of success by adding smaller amounts of fish fairly infrequently (say every 2-4 weeks).

This will allow the bacterial colonies in your filtration system to adjust to the added fish waste load, before adding again. At the point your water tests begin to show consistent levels of Ammonia/Nitrite, you either have too many fish OR are over-feeding. In order to test your water, we would recommend using a good water test kit such as this one by NT labs.

If you would like to learn more about keeping fish in tanks and how you can do this in the best way to protect your fish, read our Simple Guide to Marine Fish and Aquariums, or contact us for a chat.


How long do Juwel tanks last?

If you look after it, a Juwel tank should last you many years. All of the component parts in a Juwel aquarium are replaceable, on top of which they come with a standard 2-year guarantee. To put it simply, if you look after a Juwel aquarium, the aquarium will look after you!

For any information on spare parts, do not hesitate to get in touch with us at Complete Koi & Aquatics.


How does a Juwel filter work?

Juwel Filters have several component parts acting as both mechanical and biological filtration. Water is drawn into the filter through a grid in the plastic work where it is forced through the heater and media before entering the pump, pushing the filtered water back into the aquarium.

The water generally passes through a series of sponges with different grades (and other forms of media) which have different functions and are designed to trap different size particles, or filter out specific elements.

These sponges include:

The BioPlus and Nitrax, which are porous filter sponges designed to remove large solids from the water, while providing a good surface area for bacteria to colonise, removing Ammonia and Nitrite from the water. The Nitrax sponge is specifically designed to remove harmful Nitrite from the aquarium water.

After this is the BioCarb. This is another sponge however, this contains activated Carbon in the form of charcoal. This binds with odours, toxins and any elements which may discolour your water, thereby neutralising them.

Then there is the BioPad, which is a compact floss layer strictly used for mechanical filtration. The floss is designed to trap any fine particles before the filtered water passes into the pump, giving you that all important water clarity. At this point, it is worth remembering the BioPad is the component which will need changing most often.


Juwel provide additional medias in certain ranges of their larger aquariums however, these can also be bought as singles to modify, adapt and improve your current filtration set-up:

Phorax – This is a Phosphate remover cartridge. This is a highly efficient filtration media which is designed to reduce the amount of phosphate present in aquarium water. This reduces and controls algae blooms and can also contribute to improved aquarium plant growth.

Cirax – This is a Biological media cartridge. Cirax is a large surface area media which is strictly for biological filtration. Cirax provides the ideal environment for colonisation of filter bacteria Nitrosomonas and Nitrobacter.

Amorax – This is an Ammonia remover cartridge. Amorax is a highly efficient filtration media made of natural Zeolith. It quickly and effectively binds with Ammonia, thereby controlling any Ammonia spikes which will improve the health of both plants and fish.

All of the Juwel media range is available in Small, Medium and Large to suit the various size filtration boxes which are present across the range.


Are Juwel heaters fully submersible?

Most aquarium heaters work by being submersed, heating the water coming into direct contact with the heater. Juwel aquarium heaters work in exactly the same way and must be submersed. Do not turn on an aquarium heater before putting it into water.


Where can I buy a Juwel Aquarium?

You can buy your Juwel Aquarium, tanks, cabinets and accessories all from Complete Koi & Aquatics. We can provide expert advice relating to the set up of your tank, cleaning and maintenance. We can also advise on caring for your chosen fish, as well and recommending and supplying all of the necessary products. Take a look at our Juwel products or contact us today to learn about what we have to offer.


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