UV Filter Recommendation

John S

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13 Dec 2008
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Welwyn Garden City
For years I have run a Hozelock Titan 5500 with a Bioforce 9000 UV filter. The set up has always worked well for me and helped produce reasonably clear water. A seal failure on the filter has let water into the quartz tube. The tube has gone brown and will not clean and the electronics are probably shot. In short it’s not worth repairing. They don’t make the 9000 anymore so can anybody recommend another filter? It doesn’t have to be Hozelock, there new revolution range are out of my price range.

Cheers,
John
 

mi casa

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15 Apr 2012
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HUll
Hi dude my Hozelock filter the uv part did the same so i cut the power cable off and got a separate uv off Amazon £34 it's the Jebao 11w and it as been spot on as there was nothing wrong with the filter part it was just the uv. The hozelock was only 5w and this is 11 they go up to 55w. thats one way of doing it:)
photo-16_zps7c8bf47b.jpg
 

John S

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13 Dec 2008
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Thanks for the info. My hose size is 38mm and the fittings on these units look a lot smaller but I will search for something similar.
 

mi casa

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yes its 20 all the way up to 50mm they look small in the photo but there not :)
 

John S

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Not yet. Car needs taxing this month so will be when I get paid next. I'm looking at getting a stand alone unit like yours. :thumbup:
 

GSDF&F

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18 Sep 2013
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Brighouse
Hi mi casa, that looks a pretty good set-up. My filter looks the same as yours, but as I've just taken over the property, I'm starting from scratch with the pond. (My thread's in the "Pond" section for the info) The 5w UV tube was blown & the glass surround was heavily stained, as was the plastic outer cover for the glass tube. There were no sponge filters inside either, so I'll need to get those as well. But your reason for the "add on" has got me wondering if the seal has also gone on mine, which buying another UV lamp would be pointless, though I suppose I could easily seal the er! seal if you get my drift. Any advice most welcome.?
 

GSDF&F

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Am I right in saying the UV unit is pump fed first, then through the original filter & finally back to the pond. Er! what's the screw cap for on the top.
 

foxfish

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11 Oct 2009
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It doesn't really matter where the uv is placed, lots of people have strong views on this but not so many have experience, the screw cap is sealing an alternative outlet.
 

martin-green

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8 Aug 2011
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Am I right in saying the UV unit is pump fed first, then through the original filter & finally back to the pond.
It doesn't really matter where the uv is placed, lots of people have strong views on this but not so many have experience.
I don't want to start an argument, but I always have pump first, then UV then bio filter. The reasoning is that a UV is supposed to cause the micro organisms (that are green) to flocculate (clump together) and these get trapped in the bio filter, if you have the UV after the bio filter you are dumping the "clumped" organisms back in the pond.
 

foxfish

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Yes you are right that UV light will damage the free floating algae spores & cause them to clump together this will then be filtered out by the mechanical filter medium.

Why does this fact imply the UV has to be sited in front of the filter?

If the filter is sized correctly, then anything big enough to be trapped will be, as the continuous flow throughout the water column will eventually send any such particles into the filter.

It can be agued that placing the UV after the filter will keep the quartz glass surrounding the UV tube much clearer & therefor increase the UV efficiency?

However... as long as the system is correctly matched to the volume of water being treated it makes no 'real life' difference were the UV is placed!

As with planted tanks - a lot depends on the success of the system via the understanding of how it works but, equally, the amount of effort you are prepared to put into it.
So if you maintain a well balanced set up that has been thoughtfully put together, is makes not a bit of difference where the UV is placed.
I have found that generally speaking, folk expect an awful lot from a tiny filter compared to the size of the pond!
 

ceg4048

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The reasoning is that a UV is supposed to cause the micro organisms (that are green) to flocculate (clump together) and these get trapped in the bio filter, if you have the UV after the bio filter you are dumping the "clumped" organisms back in the pond.
This is not the mechanism by which UV disinfection occurs. UV has nothing to do with clumping and cannot affect pathogens in this manner.

Disinfection occurs when the DNA and RNA molecules of the pathogen absorbs UV photons. The most effective frequency is in the neighborhood of 250 nanometers.

The photon bombardment and absorption of the radiation energy affects the "Base Pairs" of the DNA.
Here is a schematic of a typical DNA molecule showing the famous "Double Helix" shape. The Base Pairs are the horizontal ladder steps having the symbols A, T, C, G:


All of what we are or what we will become, physically and chemically, is encoded by the sequence that the base pairs occur in. When a cell needs to reproduce or to perform a function the information on how to accomplish that function must be decoded by reading the sequence of Base Pairs, then replicating that sequence, and finally, carrying out the instructions given by that segment of the sequence.

In schematic above can be seen a molecule called "Thymine" (the purple T). It usually bonds with another molecule called "Adenine" (light grey A), thus forming an "Adenine-Thymine Base Pair."

Because the molecules are tightly packed together, absorption of UV into the DNA causes two adjacent Thymine molecules to fuse together, creating something called a "Thymine Dimer". This new molecule changes the sequence of the Base Pairs, thus causing a mutation. This new mutated set of instructions usually disrupts the function of the cell and prevents reproduction or replication of cells because the coded sequence of "how to be", "what to look like" and "what to do" become completely nonsensical, so the organism dies, or at best, cannot reproduce.

In fact, clumping is a mechanism used by microorganism to evade the effects of UV radiation because they can hide from the photon bombardment.

Theoretically, therefore, it makes much more sense to mount the UV bulb in the area of least turbid water possible which ensures maximum exposure and dwell time of the radiation upon the microorganism. There is no way any mechanical filter will remove microorganisms.

Cheers,
 

foxfish

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I really don't understand that at all & I am not sure what you are trying to say apart from contradicting me!

I am not sure how many years of experience you have had with the installation of UV filters but I have had about 30 & I can only offer my personal advice.

It makes no difference if you place the UV in front or after the pump, in front or after the filter or anywhere along the line, what makes a difference is how often you maintain your equipment, how well it is installed & how well it is sized to the pond!

More often than not, space is at a premium inside the allocated filter space, it might not be possible to choose the ultimate position of the UV ... don't worry about that.. put the UV where it avoids acute pipe bends & is easily accessible to maintain & clean the quartz.

That of course is a real word fact & not some technical fact.;)
 

martin-green

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8 Aug 2011
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ceg4048, that's easy for you to say, but could you put it in simple terms, as I for one do not understand it :nailbiting:

As far as I can understand it, you seem to be saying I am wrong, but I would point out that another person seems to agree with me, so we can not all be right can we?

I also wonder is what you say about a UV steriliser not a UV clarifier ?

I have taken them to be very similar, just that the steriliser is way more powerful, and not what is used in a pond.
 
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