# Question on using In line UV Sterilizer with Fluval FX6



## joeyo

Hello!

Need some help from FX 4, 5 & 6 community as I just ordered an Aqua UV 15 watt with 3/4" input/return and a Fluval FX6 for my 220G aquarium. This FX6 will be my secondary filter as I also have a 50-gallon wet/dry for my biological. I just called Customer Support at Fluval and asked if I could run an inline UV sterilizer. They said no, that it was never tested that way and may cause bubbles and issues long term. Then I asked about using a spray bar, they also said no to that as well.

So, that brings me to the FX 4, 5 & 6 community.

Question 1 - Is this tray set up ok: tray 1 for filter floss, tray two for the sponges and tray three for the ceramic rings. Please let me know why it may not work if so.

Question 2 - The FX6 has 1" ID hose and I want to use the Aqua UV in line. Can I reduce the line from 1" to 3/4". Does anyone see an issue with adding pressure to this gravity-fed canister filter? Or should I just upgrade the input and returns on the UV light with a 1" input and return to keep everything unrestricted.

Question 3 - Did not want to use the stock hose, intake strainer, or multi-directional return. I want to use a 3/4" PVC bar that is fitted under my overflow box as the intake into the FX6 canister and then for the return, I have the water flow from the FX6 Canister to the UV light (using 3/4' or 1") and then finally to a 6" submerged 3/4" PVC 90 directional return.

Please let me know if any of these options appear to be problematic for the FX6. I see lots of YouTube spray bars and PVC with vinyl hose custom setups, but would like to know long-term outcomes regarding performance. I've tried my hand a doing a DIY 5-gallon bucket, it failed, then I tried the 4" canister, that, too, was problematic. The FX6 is reliable, but with my customizations, I don't want to make this unreliable etc. And hoping to use the UV light and my intake and return that I had made.

Looking forward to reading some feedback about my questions. Thanks, Joe 🐟 🐟 🐟 🐟 🐟 🐟


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## CeeJay

I'll try to help you on question number 2. First off what's your purpose for uv sterilizer? If it's algae control or for parasites. Your dell time is what you need to know because for algae you can pump a lot of water thru it but for parasite you will have to slow the water down. The manufacture will list dell times for each. I run a 25 watt on about 200 gallon system and only shoot for about 150 gallon an hour I use it for parasites. I would T off from the canister and put vale in to control the amount of water I want to go thru the sterilizer. The canister won't have any problem running thru the sterilizer. It should cause very little back pressure. As far as pipe size I have gone down to 1/2" running thru the uv unit. But you should be able to plumb it with any size you want. One thing I would recommend is reading the manufacture instruction before you buy. They should be able tell what will work and what doesn't.


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## joeyo

Thanks for your response CeeJay.

In reading up on the UV for sterilization; 
The flow rate for Aqua UV's Classic 15 watt for sterilization (@30,000 uw/cm2) is 700gph.

And reading stats on the FX6 filtration rate with media is 563gph.

Both look to be good for staying in the manufacture's required parameters.

As I mentioned initially on Fluval, when I talked with their customer service, they stated their FX6 was not tested to run in line uv filtration as it may cause bubbles (in line) and they also recommended against adding spray bars. So they don't stray from their primary function, which was why I reached out to folks who use the FX line, for additional experiences. Again, thank you for your experience here.

Question 1 on media set up seems to be preference. I'm guessing the more mechanical filtration, the sooner I'll need to change /clean it.

My goal for additional filtration was water polishing.
I'll up the connections from 3/4" to 1" to reduce any unnecessary friction as well.

And my last question was using clear vinyl hose over the stock hose, but that too should be good to go. I was more concerned in adding barb reducers from 1" to 3/4",but I'll just add 1" barbs where needed.

Any other thoughts about the content above? 
Thanks, Joe


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## Pdxmonkeyboy

I'll chime in. 
I replaced the stock hoses with 1" flexible black pvc. I had to use 2 hose clamps to get it not to leak where it attaches to the filter.

spray bar... stock outlet. I can't fathom why they would be any different.. it's simply an outlet.

Now for the UV. 700gph seems really really really high. I have a 55 watt sterlizer and push 400 through it. The thing with the sterilizer is if your going to bother to run one, you might as well nuke the **** out of everything.. parasites, virus, etc. I would set it up like cee Jay said and T off your main line, reduce to 3/4, then T back in.


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## wryan

From the manufacturers perspective few things:

1. They are offering a product as a (theoretically complete) _solution_ ...

To entertain the ideas of modifying their product suggests that it may be inadequate somehow.

2. Liability/warranty.

They tell you _"Yeah, sure ... go ahead ..."_ (with said modification) and they have to consider the prospect that they may be on the hook if things go wrong. While it might be not be technically true from a legal perspective, there's always a potential public relations aspect.

3. Finally, toss into the mix the _"not-invented-here"_ syndrome ...


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## joeyo

Thanks everyone for your responses. I went ahead and bought two 1" to 3/4" barbed reducers, a 1"2' section of clear vinyl hose and did the change 10 inches off the FX6 lid input & output.

Pleased to say the FX6 pumped water through the system fine. No leaks.

Water flow is weaker as a result of the added connections, not 563gph,more like 300. I look forward to seeing the first cleaning inside the FX6!

Lastly, I wanted about to let you all know that I burned about $90 in pvc unions, pipe, elbows and hose trying to make the DIY 5 gallon bucket(canister) and then a four foot 4" pvc canister work. Each had major flaws to use as a continuous working canister filter. Just buy a working model canister filter, your better off.

Thanks, Joe


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## wryan

joeyo said:


> Thanks everyone for your responses. I went ahead and bought two 1" to 3/4" barbed reducers, a 1"2' section of clear vinyl hose and did the change 10 inches off the FX6 lid input & output.
> 
> Pleased to say the FX6 pumped water through the system fine. No leaks.
> 
> Water flow is weaker as a result of the added connections, not 563gph,more like 300. I look forward to seeing the first cleaning inside the FX6!


Keep us posted on how it works out over the long-term.



joeyo said:


> Lastly, I wanted about to let you all know that I burned about $90 in pvc unions, pipe, elbows and hose trying to make the DIY 5 gallon bucket(canister) and then a four foot 4" pvc canister work. Each had major flaws to use as a continuous working canister filter. Just buy a working model canister filter, your better off.


 :thumb:

Sometimes it is just better to bite the bullet and pony up ... :wink:


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## Whowhatwherewhenwhy

Refurbishing an old 75 gallon bow front I got for free and am planning to run this same setup with the fluval inline clarifier and am glad I came across this post I wouldn’t have thought about T-ing it off. I would need to use a T valve to control flow right?
OP how did this work for you in the long run? @joeyo


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## Whowhatwherewhenwhy

Whowhatwherewhenwhy said:


> Refurbishing an old 75 gallon bow front I got for free and am planning to run this same setup with the fluval inline clarifier and am glad I came across this post I wouldn’t have thought about T-ing it off. I would need to use a T valve to control flow right?
> OP how did this work for you in the long run? @joeyo


Would love to see a picture of you have one


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