UV sterilizer: manifold vs return pump

[DVal]

I'm looking to add a UV sterilizer for protozoa to my 220. I'm trying to decide between running it with the manifold, which I would have to go from 1/2in to 1in hose. Since protozoa requires lower flow, could this provide adequate flow? Or should I run it with its own pump?

 

[Lost in the Sauce]

Mine is run off of the manifold. No need to add additional failure points if you have an open manifold leg and you can bump up the pump

 

[Yodeling]

Not sure I understand your question, but both methods should provide "adequate" flow for sure. The flow is easier to tune with a dedicated pump (because you don't have to contend with other devices), which is why a dedicated pump is generally recommended for protozoa.

 

[Lbrdsoxfan]

I went manifold on my 40 watt uv that's on my 120 display. Previously ran on its own 250gph return pump but I wanted a single pump for everything, so I just upsized the return and went 3/4 on the manifold to the uv, with a gate valve. How big is your current return pump, can you sacrifice some gph to handle the uv?

 

[jgirardnrg]

I run the UV on my 60 cube with it's own pump and going to be running using a manifold on the new tank (Fiji 108g). Either way is fine as long as you can get the flow desired.

 

[Quietman]

For protozoa it's less critical where you run the UV. You'll want the highest exposure rate you can get but tank turnover is less important than for algae. The explosive reproduction rates for some algae can double in population every 20 min. To compensate a true 8x tank turnover per hour is needed which can be very difficult from a manifold (which only sees a fraction of return flow).

As long as it's only protozoa and you know flow rate needed for exposure you're likely fine with manifold. If you ever wanted to remove algae (dinos) you'll have to modify the setup.

Although the flow requirements for algae could be lower to prevent breakouts than to eliminate an existing issue. So a lower turnover may still help prevent. That's a logical assumption on my part based on my experience and not based on testing, data or industry doc.

 

[sdreef]

I'm looking to add a UV sterilizer for protozoa to my 220. I'm trying to decide between running it with the manifold, which I would have to go from 1/2in to 1in hose. Since protozoa requires lower flow, could this provide adequate flow? Or should I run it with its own pump?

You could do it either way.

Here are the variables I would consider:
1. The amount of UVC you want to deliver for protozoa
2. The flow required to achieve that
3. Your return pump set up
-A general consideration is the return pump should be dialed to meet your systems needs. You don't want to dial it to achieve a certain flow in the UV sterilizer if it is in line with your return. Do you have one or two pumps. If you have one, does it have sufficient power to run a manifold with proper flow for the UV and meet your systems return flow needs.

For Protozoa, different manufacturers have different recommendations:
-Pentair recommends 180,000 µW/cm2 as a target. They list a max flow based on 100% output and a recommended flow rate based on 80% at the end of the lamp's life.
-Aqua UV, on the other hand, targets 75000 - 90,000 µW/cm2 to control fish disease for their recommended flow rates.
-Lifegard provides flow rates for 30,000 µW/cm2 and doesn't provide a flow rate for fish disease, but easy to calculate based on the dose of UVC you decide to target.

There is no evidence based consensus regarding the UVC dosage required to kill marine ich theronts that I am aware of, but if anyone knows a good reference, please share.

In my own system, I have two return pumps and target 3 times turnover through the sump. Based on the known flow rate through each return line, I selected a UV sterilizer that would deliver at least 180,000 µW/cm2 for that given flow. I run one UV sterilizer in line with one of my return lines. I preferred not to run off a manifold because I would need to run the return pump at a higher rate requiring more energy and also return the water to the sump resulting in more recycled water passing through the UV sterilizer. This likely isn't very important in any net effect for the system and is acceptable, but it was a little less efficient for my setup.

 

[DVal]

I went manifold on my 40 watt uv that's on my 120 display. Previously ran on its own 250gph return pump but I wanted a single pump for everything, so I just upsized the return and went 3/4 on the manifold to the uv, with a gate valve. How big is your current return pump, can you sacrifice some gph to handle the uv?

I'm running a varios 8. Shouldn't be a problem sacrificing a little bit of flow.

 

[DVal]

For protozoa it's less critical where you run the UV. You'll want the highest exposure rate you can get but tank turnover is less important than for algae. The explosive reproduction rates for some algae can double in population every 20 min. To compensate a true 8x tank turnover per hour is needed which can be very difficult from a manifold (which only sees a fraction of return flow).

As long as it's only protozoa and you know flow rate needed for exposure you're likely fine with manifold. If you ever wanted to remove algae (dinos) you'll have to modify the setup.

Although the flow requirements for algae could be lower to prevent breakouts than to eliminate an existing issue. So a lower turnover may still help prevent. That's a logical assumption on my part based on my experience and not based on testing, data or industry doc.

Thanks for the input. The main goal is ich control, or atleast to knock it down a little. I've got a powder brown with it, luckily no one else has it. Can't really go fallow...so just looking for something to help since I know it's lurking in the tank. If I change it up to treat algae, I can add a pump to up the flow.

 

[DVal]

You could do it either way.

Here are the variable I would consider:
1. The amount of UVC you want to deliver for protozoa
2. The flow required to achieve that
3. Your return pump set up
-Some general consideration are the return pump to meet your systems needs, not be dialed based on UV dosage. Do you have one or two pumps. If you have one, does it have sufficient power to run a manifold with proper flow for the UV and meet your systems return flow needs.

For Protozoa, different manufacturers have different recommendations:
-Pentair recommends 180,000 µW/cm2 as a target. They list a max flow based on 100% output and a recommended flow rate based on 80% at the end of the lamp's life.
-Aqua UV, on the other hand, targets 75000 - 90,000 µW/cm2 to control fish disease for their recommended flow rates.
-Lifegard provides flow rates for 30,000 µW/cm2 and doesn't provide a flow rate for fish disease, but easy to calculate based on the dose of UVC you decide to target.

There is no evidence based consensus regarding the UVC dosage required to kill marine ich theronts that I am aware of, but if anyone knows a good reference, please share.

In my own system, I have two return pumps and target 3 times turnover through the sump. Based on the known flow rate through each return line, I selected a UV sterilizer that would deliver at least 180,000 µW/cm2 for that given flow. I run one UV sterilizer in line with one of my return lines. I preferred not to run off a manifold because I would need to run the return pump at a higher rate requiring more energy and also return the water to the sump resulting in more recycled water passing through the UV sterilizer. This likely isn't very important in any net effect for the system and is acceptable, but it was a little less efficient for my setup.

Thank you for the response. Very good info. I'm looking at a Pentair for my 220. Currently running a varios8 return, which has a max flow of 2700gph. I'm curtently running a carbon reactor off of the manifold now. I would imagine that would still provide adequate flow to the UV while still providing enough flow to the tank.

 

[Quietman]

Thanks for the input. The main goal is ich control, or atleast to knock it down a little. I've got a powder brown with it, luckily no one else has it. Can't really go fallow...so just looking for something to help since I know it's lurking in the tank. If I change it up to treat algae, I can add a pump to up the flow.

If you have a breakout now, I would suggest as a temporary measure, just getting a simple pump (cheap dc can be fine only needs to last a couple weeks) and hose and placing supply end and return end directly in your tank (closed UV loop) for a couple weeks until the symptoms go away. You'll get the high exposure and the turnover to maximize the impact.

Once it's under control then you can switch to permanent 'management' mode off of manifold.

Like this guy (serious overkill on the UV unit here but he's running a service).

 

[DVal]

If you have a breakout now, I would suggest as a temporary measure, just getting a simple pump (cheap dc can be fine only needs to last a couple weeks) and hose and placing supply end and return end directly in your tank (closed UV loop) for a couple weeks until the symptoms go away. You'll get the high exposure and the turnover to maximize the impact.

Once it's under control then you can switch to permanent 'management' mode off of manifold.

Like this guy (serious overkill on the UV unit here but he's running a service).

I'll do just that. Thank you