Blagdon 9W Mini-Pond 6-Stage Box Filter 12000 Litre Model with UV Clarifier Light, for Ponds Up-to 12,000 Litres


The Minipond 12000 Box Filter is made for ponds containing up to 12,000 litres of water. However, many factors should be considered to make sure this is the right size filter for your pond and equipment. See image 7 in the product details at top of page for a full explanation. The siting of your pond (shade or full sun for instance) and whether or not you have fish should all be things to consider when you select your filter. Full sun will mean more algae and fish will create waste.

Make sure you use compatible hose. The outlet hose should be heavy duty smooth bore (not corrugated) pipe installed over as short a distance as possible with no kinks or bends.

The pump supplying the Minipond filter must not have a pumping head exceeding 4m – 0.4 Bar.

The maximum flow rate recommended is stated in the filter performance and specification chart. This flow should not be exceeded.

The ideal flow rate for your pond is to pump the volume of the pond water through the filter every 2-4 hours.

To increase flow you may need to get a larger pump. If flow is too high use an inline valve to reduce it.

The purpose of the pump is to transfer dirty water from the pond to the Minipond filter.

Placing the pump at the opposite end of the pond to the filter will give the best results.

Foam-free pump designs will give optimum Minipond filtration.

We recommend Blagdon Pond Pumps for fountains, filters and waterfalls.

blagdon mini pond box filter with uv clarifier cleaner steriliser sterilizer water algae remove foam

Install below or above ground (filter must be above water level)

Whichever choice you make it is important to make sure the filter is above the level of the water for water to return to the pond via gravity.

blagdon pond filter clean pond algae remover uv clarifier lamp light water cleaner
blagdon pond filter uv clarifier sterilizer steriliser algae remover sludge pond


Dimensions: 47.4 x 39 x 35.5 cm; 4.8 Kilograms
Model: 12000
Part: 12000
Manufacture: Blagdon

27 Responses

  1. Joanne says:

     United Kingdom

    This cleared my pond within a few days but the foam filters need cleaning at least once a week to keep it working properly. Very easy to do.

  2. MariaFreedman says:

     United Kingdom

    I have had many filters over the years but this one is the best and easiest to use and maintain.
    The water cleared within hours and has remained the same ever since.
    What is important to know though is to make sure your pump is the right size for your filter otherwise the filter doesn’t do what it’s meant to. Where the sponges are in the main compartment should not overflow into the smaller second compartment. This happened to me to start with because my pump was too strong and I sorted this by purchasing a Blagdon tap to slow the flow down.
    It is also important to clean the filters regularly which takes about 30 minutes, simply by removing the sponges and the cartridge and spraying them clean with a hose.
    I’ve had filters in the past which took ages to clean and were very fiddly. This one is so easy.
    I have purchased spare sponges and cartridges to change in the months ahead and they are all available via Amazon. I intend to keep this filter well maintained going forward to save the hassle of emptying a green water pond.
    I have also purchased a Blagdon oxygenator but I’m sure regular maintenance of this filter would do the job alone. See the photos this is how clear my pond is. Well impressed with this product.
    It’s now March 2022 and my water is still nice and clear.

    Best Filter Easy to use

  3. OQRStanley says:

     United Kingdom

    Cleared really murky water in a few days. Pond look great.

  4. Anonymous says:

     United Kingdom

    Sceptical at first, but using this filter which is surprisingly compact but the right size for my pond. I also added two mall bales of Barley Straw but judging by the what the filter had strained out of the pond it really did a good job and I can now enjoy seeing my fish at the bottom of the pond.

  5. Anonymous says:

     United Kingdom

    I was suffering with a pond that had gone like pea soup and i struggled to see my fish. I opted to change my old filter unit to the Blagdon MiniPond 12000 as it had a 9 watt uv light. Easy to set up and looks easy to maintain the unit and the uv light is simple to get to. Started to see improvement in 4 days and within 2 weeks I can cannot only see my fish I can also see every bit of gravel on the pond floor (24 inches deep).
    So I’m well pleased and so are my fish. Would definitely recommend

  6. Antoine9717 says:

     United Kingdom

    My pond water was clear to begin with but my old gravity filter (different brand) was worn out. It ran a 24w bulb, this runs 9w and is fine as long as I keep on top of cleaning the filters.
    I have a lot of fish and so I have to clean the filters every other day. I wish the Supra/blocks at the bottom were easy to remove. The instructions say clean once a year but once a month is more realistic. A removable container would make it so much easier.
    I’m also disappointed that the small front filters require replacement every month. That should be factored in to anyone purchasing this model.

  7. Anonymous says:

     United Kingdom

    What can i say great cleared my pond in under a week

    Does what it says

  8. Anonymous says:

     United Kingdom

    Well Happy took 7 days to clear as heavy green water could not see NOW cystall ckear see every detail thorough water, must be tons better for the fish . They look well happy.

  9. RandySilverman says:

     United Kingdom

    My pond was murky and this cleared it up to crystal clear in two days. My pond is 1200ltr and I am operating it with a 2000ltr pump. Overkill but works well.

  10. Anonymous says:

     United Kingdom

    Direct replacement for a previous model. Easy to install- totally satisfied.

  11. SaundraCwm says:

     United Kingdom

    Worth the money but I thought it would be bigge

  12. saving coupon uk – Новини Google says:

     United Kingdom

    Golden Review Award: 3 From Our UsersMoving into my new property and a novice garden pond owner, I was worried if I was able to find a UV pond filter system to replace my old broken one. I’m so relieved that with some minor adjustments to pipe work and wiring, I did this with no difficulty at all. It only took me an hour. My only challenge was that I had to establish that a 40mm pipe was needed as at outflow pipe and not the bigger size my previous filter system used.
    The system is really impressive and has been manufactured to high standard. It has been designed brilliantly with the need for easy access to clean filters without causing wear and tear to any pipes or wiring, a problem that I encountered on my previous filter system.

  13. Lakeish9772 says:

     United Kingdom

    A replacement for an old filter I oversized and was glad that I did for the small amount extra as it’s not actually that big physically.. relatively easy to set up, and clean, just watch that you have enough spare cable to tip it on its side to clean the bottom out. Overall pleased with it and it seems to be doing the job of keeping the pond clear if I clean it out weekly.

  14. silvergirl says:

     United Kingdom

    I’ve had 2 of these for over 5 years. I change the UV bulb every spring and clean the filter with rain water and a vacuum cleaner to avoid leaving any sludge at the bottom. I do not use the wool filter any longer as it clogs up too quickly but my water is still clear. I have put active carbon pellets in the filter instead of the expensive Minipond one. The Ph of my pond was too low so I put some chicken grit in the filter to reduce the acidity.
    A pond vac is a must for cleaning out the filter and also the pipe from the pump.

  15. AlisaLetbepyrk says:

     United Kingdom

    Had this product for five years now,had to replace pump last year,pump and filter run 24/7,through t, the summer months,water is as clear as tap
    water,change wool filter daily,and swap 3 stage filters weekly,I have been very pleased with filter,and I would recommend for the average pond
    circa 1500 to 2000 ltrs.

  16. Anonymous says:

     United Kingdom

    Excellent item. Purchased as as an exact replacement which I had previously had for for nearly 8 years, so hopefully this will last the same.

  17. Anonymous says:

     United Kingdom

    I am happy with the filter, it makes the water perfectly clear. I recommend Blagdon filters and uv sistems for small and large ponds.
    Thanks for the fast delivery.
    Green At Home Ltd
    greenathome.co.uk

  18. Anonymous says:

     United Kingdom

    Golden Review Award: 2 From Our UsersVery good and now my murky pond is way better. I have a 1000 litre pond with a pump capable of around 1600litres per hour and around 15 gold fish so wanted something better than my old green genie.

    This is great along my oase pump, but needs regular cleaning. Not a bad price to pay for a clean pond.

  19. Anonymous says:

     United Kingdom

    Brilliant filter cleared the thick green sludge to beautiful clear water in 10 days

  20. LewisL01ixvexu says:

     United Kingdom

    This pond filter is excellent ,cleared my pond in just 2 weeks ! after which I cleaned it out ,really mucky by then as the pond was like soup before,however this was really easy to do as long as you have access to a running tap, 15 minute job
    I can now see clear to the bottom of the pond ,much to the delight of 2 yr old granddaughter watching the antics of the fish and frogs!!

  21. Anonymous says:

     United Kingdom

    Golden Review Award: 5 From Our UsersI have had a small above-ground pond for over a year and was fed up of having murky water and not being able to see the goldfish, in spite of having oxygenating plants and a filter ( no UV ).
    First of all I bought an Oase Pondomatic vac and cleared all the debris from the pond bottom. Then I changed the filter to the Blagdon Mini-pond filter. Wow, the results have been amazing; crystal clear water in less than 2 weeks. This really does work.
    Both items were from Amazon at great prices and delivery. I have also bought barley hay but I don’t think this can improve on the water quality.

  22. Anonymous says:

     United Kingdom

    Cleared my green murky pond in 5 weeks. Very neat, doesn’t look big enough but works perfectly. Will buy another for our smaller pond.

  23. IgnacioHAH says:

     United Kingdom

    Had to replace an old pond filter that had come to end of life after several years usage.

    I didn’t realise Blagdon had their own range of pond filters. I’m so glad to of discovered this filter as it is a quality filter. It’s very easy to assemble and maintain. Often with my old pond filter was a real task to clean it! With Blagdon it’s very easy to clean and access filter foam you need to clean.

    The UV filter light is also easily accessible, without need to take apart the filter like some pond filters could mention, aiding to quick and easy replacement of UV light when needed.

    Having several Koi Carp it’s important the water is kept in good health and clean. This products achieves this with top marks!

    It’s also very quite too! no real filter noises apart from running water! There’s also an add on rocky top to hide the filter which is a recommended add o

  24. MicahZoegk says:

     United Kingdom

    Golden Review Award: 2 From Our UsersIdeal for my purpose and is now working very well. Took a little time to get working as pond very murky, but is now very clear.

  25. VincentAdair says:

     United Kingdom

    Golden Review Award: 5 From Our UsersHad loads of trouble with green pond water for years. I have tried every liquid & powder to try to eliminate it – but got nowhere. Bought this kit and within two weeks my pond water has become crystal clear. I have small pond (about 5000 litres) and only run the filter for approx 4/5 hours per day but it keeps the water clear. Best thing I’ve bought in years !.

  26. Jimmy Vielkind Capitol bureau says:

     United Kingdom

    This is more or less perfect for a small pond, but the only problem I seem to have the UV Clarifier does seem to go wrong a lot, it is only 6 months old and already it has had to be replaced – Blagdon was very good and replaced it for me, although they told me I should have gone via the supplier. Maybe I was unlucky, so if you do buy one (and it is good) make sure you keep your receipt handy for the guarantee.

  27. Anonymous says:

     United Kingdom

    Golden Review Award: 3 From Our UsersThis is a first class filter. Cannot recommend it enough. My pond has been murky for a long time but not any more.