Plumb UV through a manifold

Ian Baxter

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I’m looking to hook up my Aqua Ultraviolet 25watt uv to mainly combat ich on my 200g. Can it be done using a manifold on my return? My return pump is a Vectra L2. Hope this photo helps. The first 90 turn goes from the front of the sump toward the back, then a 45 to the left, and a 90 into the display. All piping is 3/4.

IMG_0581.jpeg
 

UncommonSense

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I’m looking to hook up my Aqua Ultraviolet 25watt uv to mainly combat ich on my 200g. Can it be done using a manifold on my return? My return pump is a Vectra L2. Hope this photo helps. The first 90 turn goes from the front of the sump toward the back, then a 45 to the left, and a 90 into the display. All piping is 3/4.

IMG_0581.jpeg
So, this sterilizer is undersized for your tank, particularly for a in-line plumbing application! (150-200gph for parasites)

This topic has been discussed in great detail many times before around here if you do a quick search, but the gist is that the above diagram simply doesn’t work reliably (or often at all) without adding at least two valves…

— Simply put, both inlet and outlet of the sterilizer are under equal pressure in the above plumbing configuration, meaning there will be no appreciable flow through it!

— a valve for both the return line and the sterilizer line would allow you to restrict return flow to bypass some through the sterilizer, but this also isn’t a very good way of plumbing this… (you can’t really tell what flow rate the UV sterilizer’s at without a flow meter plumbed in-line, for example)

— your return pump is extremely oversized for 3/4” plumbing, and is loosing at least 70% of its flow potential to frictional loss… 1.25” plumbing would be better, 1.5” ideally!

— the simplest solution with the sterilizer you have would be running a second set of return plumbing off a small return pump up to the DT!

— the “perfect world” solution would be re-plumbing the main return to 1.25”-1.5” PVC, and using a 100-240W UV sterilizer plumbed directly in-line!



Example sterilizer that will still affect parasites at 1,300-1,500GPH:

 
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Ian Baxter

Ian Baxter

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So, this sterilizer is undersized for your tank, particularly for a in-line plumbing application! (150-200gph for parasites)

This topic has been discussed in great detail many times before around here if you do a quick search, but the gist is that the above diagram simply doesn’t work reliably (or often at all) without adding at least two valves…

— Simply put, both inlet and outlet of the sterilizer are under equal pressure in the above plumbing configuration, meaning there will be no appreciable flow through it!

— a valve for both the return line and the sterilizer line would allow you to restrict return flow to bypass some through the sterilizer, but this also isn’t a very good way of plumbing this… (you can’t really tell what flow rate the UV sterilizer’s at without a flow meter plumbed in-line, for example)

— your return pump is extremely oversized for 3/4” plumbing, and is loosing at least 70% of its flow potential to frictional loss… 1.25” plumbing would be better, 1.5” ideally!

— the simplest solution with the sterilizer you have would be running a second set of return plumbing off a small return pump up to the DT!

— the “perfect world” solution would be re-plumbing the main return to 1.25”-1.5” PVC, and using a 100-240W UV sterilizer plumbed directly in-line!



Example sterilizer that will still affect parasites at 1,300-1,500GPH:

This helps a lot! Thank you.

Not sure why the previous owner plumbed it with 3/4 return piping. He gave me that UV with it, so I just assumed it was the right size.

So my best two options would be to get another pump and have it plumbed up over the back of the tank into the display. Or get the larger unit and plump in line with the return and add the larger plumbing.

I want to add the larger piping anyway and the drain lines are much larger, so I assume the return bulkhead should be the same. It kind of looks like he used a reducing piece from the pump and another one at the bulkhead. 🤦🏻‍♂️
 

UncommonSense

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I want to add the larger piping anyway and the drain lines are much larger, so I assume the return bulkhead should be the same. It kind of looks like he used a reducing piece from the pump and another one at the bulkhead.
Just be sure to really look carefully at the size of the bulkhead fittings going through the tank glass, they will dictate how large the plumbing can be before it’s no longer useful!
 

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