UV Sterilizer installation PVC design check up

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Boosterman

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Hi,

I'm trying to plan ahead for a new tank and I am looking to get some feedback on what I think would work in terms of UV Sterilizer installation.

The main goal here is to dial the flow to UV as needed between Algae(High flow) and Protozoans(Low flow) using ball valves.

Ideally, I'd set the flow as high flow day to day but use low flow as needed. As you can see in the drawing, I create a closed loop by having all of my water pass through the UV Sterilizer before going into the DT. With the help of the flow meter right after UV Sterilizer and the bypass flow controlled by ball valve, I think this would work but I'd like to get someone either who had done this before or is familiar with PVC plumbing.

I really appreciate it!

UV Drawing.jpeg
 
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Quietman

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I love the design/planning phase. It's also the cheapest phase. :)

It's only a 'closed loop' if the intake and return are taken directly from the display tank. You may be doing that but it's not obvious here. If not then this likely won't work well for algae as you need an high tank turnover rate (approx 8x) to keep up with reproduction rate of some alga (dinos)/bacteria.

Since you've shown 75 gallon and that happens to be what I'm looking at for next tank I've crunched some numbers. You'll need a 600 gph true tank turnover for algae (and not just flow rate). With a true closed loop if you install a 40w or higher UV (i'm going with 57 w) unit you can achieve both high turnover and high exposure for pathogens and use the same flow rate. Some of this depends on manufacturers recommendations and guidance on exactly what high end exposure is required is a bit vague (why I'm going with 57 watt).

My numbers are from AquaUV (Pentair has similar but a bit higher recommended)

You're setup can work for pathogens (ich/velvet) only since the reproduction rate is less and the main concern is maximizing exposure.

I always recommend a closed loop for only UV if you're in design phase. That's all it's going to do so it can maximize effectiveness. I really believe in the UV technology but it needs to be understood in relation to the organisms being managed/controlled to be effective.
 
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It's only a 'closed loop' if the intake and return are taken directly from the display tank. You may be doing that but it's not obvious here. If not then this likely won't work well for algae as you need an high tank turnover rate (approx 8x) to keep up with reproduction rate of some alga (dinos)/bacteria.

Since you've shown 75 gallon and that happens to be what I'm looking at for next tank I've crunched some numbers. You'll need a 600 gph true tank turnover (and not just flow rate). For a true closed loop if you install a 40w or higher UV (i'm going with 57 w) unit you can achieve both high turnover and high exposure for pathogens and use the same flow rate. Some of this depends on manufacturers recommendations and guidance on exactly what high end exposure is required is a bit vague (why I'm going with 57 watt).

My numbers are from AquaUV (Pentair has similar but a bit higher recommended)

You're setup can work for pathogens (ich/velvet) only since the reproduction rate is less and the main concern is maximizing exposure.

I always recommend a closed loop for only UV if you're in design phase. That's all it's going to do so it can maximize effectiveness. I really believe in the UV technology but it needs to be understood in relation to the organisms being managed/controlled to be effective.
Thanks for the feedback. Maybe I misunderstood the term 'closed loop.' I'm taking water from the sump and returning to the display tank.

I'm planning on using Pentair 25W and their recommended flow rate for Algae is 472GPH/788GPH (Suggested*/Maximum) which I think is achievable with Vectra S2. Do you still think this setup won't work for Algae control?
 

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Thanks for the feedback. Maybe I misunderstood the term 'closed loop.' I'm taking water from the sump and returning to the display tank.

I'm planning on using Pentair 25W and their recommended flow rate for Algae is 472GPH/788GPH (Suggested*/Maximum) which I think is achievable with Vectra S2. Do you still think this setup won't work for Algae control?
"Closed loop" used to be much more popular for flow to keep the older style big power heads out of the tank. So the term is from there. And it refers to no water to the 'open component of a sump. Just a direct pipe from display through the pump (and UV in our case) and back to display. A dedicated line if you will.

Understand that some of the algae will have reproduction rates of doubling population in 20 min. To keep up with that effectively you need a higher tank turnover than most sumps are designed for. Now you are lucky with a 75 gallon as a 600 gph (to support entire tank volume going through the UV 8x an hour) sump flow isn't too high to work and you can put the UV in line with return.

Here's where I wish the manufacturers would publish lamp life curves. The Pentair 25w UV unit that has exposure rate for algae of 472 gph (which I believe with Pentair is the 30Kuw/cm2 at 80% of lamp effectiveness - End of Life). The 788 gph is new lamp. So for perhaps 90% of life if you adjust flow that could provide sufficient flow rate yes. But the 25 w unit needs 100 gph flow to be effective for pathogens. If you want to adjust flow to address specific issues, that 25 w unit can work.

I recommend a bigger UV unit with one flow that can do both pathogens and algae continuously.

Edit - However, you may have plans to implement a rigid quarantine protocol so the pathogen mgmt with UV is less important to you. Everyone's system is different or has different management goals in mind.
 
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Boosterman

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If you have planned around maintinace you will be good.
The UV Sterilizer will be installed outside of the sump area and mounted on the wall so that I can replace the bulb once a year and clean the quartz sleeve without having to worry about removing the housing. Now.. that's the only maintenance right? lol
 

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Thanks for the feedback. Maybe I misunderstood the term 'closed loop.' I'm taking water from the sump and returning to the display tank.

I'm planning on using Pentair 25W and their recommended flow rate for Algae is 472GPH/788GPH (Suggested*/Maximum) which I think is achievable with Vectra S2. Do you still think this setup won't work for Algae control?
It can work for algae as long as you are sending 600-700gph through the sump and directing it all through the UV on the return. The question is whether or not your sump can handle the flow. Also don't forget to add in your sump water volume. 75g tank with sump could be 85g total depending on how much rock you add which take up space in the tank, and how big the sump is.

As far as your plumbing control yes the valves will work to control your flow. I would recommend gate valves though instead of ball valves.
 
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It can work for algae as long as you are sending 600-700gph through the sump and directing it all through the UV on the return. The question is whether or not your sump can handle the flow. Also don't forget to add in your sump water volume. 75g tank with sump could be 85g total depending on how much rock you add which take up space in the tank, and how big the sump is.

As far as your plumbing control yes the valves will work to control your flow. I would recommend gate valves though instead of ball valves.
It's WB Frag 105.4 with sump volume of about 30 gallons. I hope the sump can handle 600-700 ghp with Vectra S2.

Thanks for the suggestion on the gate valve! I did not think about that. I'll replace the bypass PVC to gate valve for more precise control.
 

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Lastly regarding the pump. Hard to say as it depends on height difference between sump and nozzle in display, type of nozzle, piping bends. DC pumps usually have a sharper flow decline vs head loss. I suspect you may have to run the S2 at near 100% to get the flow rate needed. Check with S2 users for input. You may want a level up or it maybe fine - close call.
 
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Lastly regarding the pump. Hard to say as it depends on height difference between sump and nozzle in display, type of nozzle, piping bends. DC pumps usually have a sharper flow decline vs head loss. I suspect you may have to run the S2 at near 100% to get the flow rate needed. Check with S2 users for input. You may want a level up or it maybe fine - close call.
Ok thanks. I will look into it to see if I need to upgrade to M2. Planning ahead is so easier with inputs from people like you! Greatly appreciate it.
 
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The UV Sterilizer will be installed outside of the sump area and mounted on the wall so that I can replace the bulb once a year and clean the quartz sleeve without having to worry about removing the housing. Now.. that's the only maintenance right? lol
Yeah outside the sump and able to open and drain, change bulb is pretty much it. But its the worst once a year if your are not fully prepared!

Best of luck.
 

Dennon 2010

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I am wondering if the growth rates of algae as stated, some doubling every 20 minutes, assumes bright light (sufficient to support coral)? If this is in fact the case, then running a sterilizer 24/7 at lower flow rates than recommended, should still be effective. Would the sterilization process not effectively catch up during the 12 to 16 hours that the display tank lights are off?

I have a RSR250 and am in the process of plumbing in an Aqua 25 watt sterilizer. I am opting for low flow and disease management. The unit is oversized for this purpose but it is unlikely that I can achieve the algae kill flow rates. The supply water will be coming from the weir box and will be returned to the sump through the skimmer. I am reasonably sure that my filtration is overkill so I am not concerned about flow rate through my skimmer. Any thoughts on this? Or actual research would be even better. Thanks
 
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