55w UV Flow Rate - Lifegard

[Kyle Bruin]

So I have been reading about sizing UV for my tank and hope someone can check my “math”. I ended up getting the 5” amalgam 55w lifegard uv sterilizers for my Waterbox 130.4, probably has a true water volume around 100-110 gallons. My goal is level 2 or fish disease sterilization.

So first turn over, 3-4x which gives 300 - 440 gph target flow rate.

Check that vs a wattage rating, 5.4-8 gph/w

Now, it’s rated at max 2100 gph for 30,000 uW/cm2. To get to an 180,000 exposure rate, I derate by 1/6th so 350 gph.

So my game plan is to run this absolutely massive sterilizer at ~350 gph. And I do mean massive. It’s why I’m here having someone sanity check me. It’s giant and seems way oversized for my smallish 110g 4‘ aquarium and 350 Gph seems slow for it.

Another thought is that the only difference between the 3” and 5” 55w unit from lifegard is the “max flow”. The 30,000 uW/cm2 is the same for both. My understanding is that the larger 5” allowed for greater dwell time. I happened to only opt for the 5” because it was slightly shorter which better suited my stand.

Any thoughts? Does 350 gph sound right? Should the 3“ and 5” have the same 30k gph rating?

 

[amps]

I can't speak to your math but I run the same Lifegard UV unit on my 180g and keep it around 400gph. I can anecdotally say that it's been effective at that flow rate. My uglies period is much much better than when cycling the same tank 4 years ago without the unit.

 

[Kryptonian]

So I have been reading about sizing UV for my tank and hope someone can check my “math”. I ended up getting the 5” amalgam 55w lifegard uv sterilizers for my Waterbox 130.4, probably has a true water volume around 100-110 gallons. My goal is level 2 or fish disease sterilization.

So first turn over, 3-4x which gives 300 - 440 gph target flow rate.

Check that vs a wattage rating, 5.4-8 gph/w

Now, it’s rated at max 2100 gph for 30,000 uW/cm2. To get to an 180,000 exposure rate, I derate by 1/6th so 350 gph.

So my game plan is to run this absolutely massive sterilizer at ~350 gph. And I do mean massive. It’s why I’m here having someone sanity check me. It’s giant and seems way oversized for my smallish 110g 4‘ aquarium and 350 Gph seems slow for it.

Another thought is that the only difference between the 3” and 5” 55w unit from lifegard is the “max flow”. The 30,000 uW/cm2 is the same for both. My understanding is that the larger 5” allowed for greater dwell time. I happened to only opt for the 5” because it was slightly shorter which better suited my stand.

Any thoughts? Does 350 gph sound right? Should the 3“ and 5” have the same 30k gph rating?

I'm running the 3" 55 Watt Amalgam at 300 GPH on a Waterbox Reef Pro 180.5. It's doing wonders on water quality. I'm just starting a battle with dinos but it's helping a lot. You're right, this thing is massive. I couldn't fit it under the tank and actually drilled through the wall behind the tank and mounted in a closet.

Wish I could give you more insight into the actual math right now. I'll check back when I have time to review numbers.

 

[Kyle Bruin]

Those are both good data points. Are either of you sending the uv treated water back to the display or does it exit back to the sump?

 

[ReefHog]

The ProMax UVs are good units. I have the 90watt myself on my 220. I think you’d have no problem running it at 400/440gph for level 2 sterilization with a 55watt. Keep in mind that the flow needs to be confirmed. Head pressure, fittings pipe size all reduce flow. I use a Neptune flow sensor right after my UV. Also for level 2 sterilization it’s best if 100% of the flow goes through the UV between the return pump and the display tank.

 

[Kyle Bruin]

The ProMax UVs are good units. I have the 90watt myself on my 220. I think you’d have no problem running it at 400/440gph for level 2 sterilization with a 55watt. Keep in mind that the flow needs to be confirmed. Head pressure, fittings pipe size all reduce flow. I use a Neptune flow sensor right after my UV. Also for level 2 sterilization it’s best if 100% of the flow goes through the UV between the return pump and the display tank.

Yah that's my ideal solution as well, thou I feel like I want higher overall turnover of my tank than 4x (400-440). Certainly would be easier and require a smaller pump if I just send flow through the UV back to my display return. Then the only manifold I need is for a reactor. Probably could scale back down to an M2 Vectra or Vario 6.

Ideally I'd like a 5-6x turn over back to my display.

 

[undermind]

Hey @Kyle Bruin what did you end up doing? I've got a very similar situation, and was curious about most all of the same things (flow rates, return to DT vs sump, etc)

 

[Miller535]

I run that same UV on my 125 gallon. I run it closer to 1,000 gph. But I was doing it for dino. I will add that it makes me tank run hot sometimes. It is basically a 55 watt heater that never turns off. Keep an eye on that.

 

[Kyle Bruin]

Hey @Kyle Bruin what did you end up doing? I've got a very similar situation, and was curious about most all of the same things (flow rates, return to DT vs sump, etc)

So I got the 5” 55w amalgam UV. It is a freaking cannon. Like comically big. I laughed at myself for an hour when I unpacked it. I actually haven’t set it up yet due to a longstanding issue with my sump, but I plan to plumb my main return through it and hope to send 6-800 gph through it.

 

[undermind]

but I plan to plumb my main return through it and hope to send 6-800 gph through it.

What made you scale up the GPH from your original plan? Is it that you'd like more turnover?

I'm close to pulling the trigger on the same unit. And I'm at about the same water volume (100g).

I'm a little thrown off by the manufacturer flow rate for algae though. 2100gph seems pretty high compared to the 943gph suggested rating by Pentair for their 40w Smart UV. Lifegard rates their 55w for up to 350g aquariums. But I'm not sure whether you can lower the 2100gph based on tank size. For example, is 30,000 μW/cm2 of UVC at 2100gph on a 350g tank equivalent to 598gph on a 100g tank? That's just reducing both gph and tank size by 28 percent - the difference between tank sizes.

I'm thinking that the gph rating at 30,000 μW/cm2 doesn't change regardless of tank size though, is that correct?

 

[t5Nitro]

Glad to find this thread today. My cheap pUV green machine pump quit working. Looking at the 54 watt for my 75 gallon. Debating putting the UV outside the tank to the external stand. What kind of pump would you put on to be able to pump from sump to outside the tank stand and back? 3 ft 75.

 

[Kyle Bruin]

What made you scale up the GPH from your original plan? Is it that you'd like more turnover?

I'm close to pulling the trigger on the same unit. And I'm at about the same water volume (100g).

I'm a little thrown off by the manufacturer flow rate for algae though. 2100gph seems pretty high compared to the 943gph suggested rating by Pentair for their 40w Smart UV. Lifegard rates their 55w for up to 350g aquariums. But I'm not sure whether you can lower the 2100gph based on tank size. For example, is 30,000 μW/cm2 of UVC at 2100gph on a 350g tank equivalent to 598gph on a 100g tank? That's just reducing both gph and tank size by 28 percent - the difference between tank sizes.

I'm thinking that the gph rating at 30,000 μW/cm2 doesn't change regardless of tank size though, is that correct?

I believe there is a max flow rate that my sump and weir can handle without being too loud. I’ve run it at 500 and had no problem. I really don’t want to get much higher than 6-800 due to that. I’m confident I will get sufficient dosage at that flow rate.

As for the math, I believe the uvc dosage (uW/s) is tied to gph but not system volume. Diameter of the uv system, high output (amalgam) bulb, etc all play into that dosage and increase contact time. I think the system volume they give is more of a suggested gph for a given system volume. So turn over does matter, but doesn’t directly change that dosage number.

I think the decision process is: chose your desired turn over rate 5-6x or say 10x if you are doing triton. That gives you your gph. Then chose your uv wattage (and things like bulb type, diameter etc) to get the required dosage you want. Lastly make sure the form factor of what you chose will fit. I regret getting the 5” diameter but I think I needed to as I didn’t have much length for 55”.

In summary,6-800 gph will give me 6-8x turnover and will give a high enough dosage to probably kill ich. Not a perfect calculation but feels right. Could probably do okay with one size down too. I oversized I think.

 

[ReefHog]

FYI, I run my 90 watt Pro Max at a flow rate for level two sterilization for parasites and after I got it up and running there was an almost instant water clarification effect and I could go two or three times longer between cleaning the front glass. There was also less algae on the rocks as well so even though it is not set up for the ideal flow for algae, it still does help.

 

[lantisbred]

I'm running the 3" 55 Watt Amalgam at 300 GPH on a Waterbox Reef Pro 180.5. It's doing wonders on water quality. I'm just starting a battle with dinos but it's helping a lot. You're right, this thing is massive. I couldn't fit it under the tank and actually drilled through the wall behind the tank and mounted in a closet.

Wish I could give you more insight into the actual math right now. I'll check back when I have time to review numbers.

I'm running the 3" 55 Watt Amalgam at 300 GPH on a Waterbox Reef Pro 180.5. It's doing wonders on water quality. I'm just starting a battle with dinos but it's helping a lot. You're right, this thing is massive. I couldn't fit it under the tank and actually drilled through the wall behind the tank and mounted in a closet.

Wish I could give you more insight into the actual math right now. I'll check back when I have time to review numbers.

Curious to hear more as I have the exact same tank and just installed the same UV unit off my return for a 100% of my water return. Problem is my return pump only gets me a max of 500gph flow though the sterilizer and Lifegard’s chart shows 2100gph for algae. I want to clarify rather than kill Protozoa.... do you think I need a higher flow or is your 300goh working well still for you? Any concerns about pods getting nuked at that flow?

 

[Kryptonian]

Curious to hear more as I have the exact same tank and just installed the same UV unit off my return for a 100% of my water return. Problem is my return pump only gets me a max of 500gph flow though the sterilizer and Lifegard’s chart shows 2100gph for algae. I want to clarify rather than kill Protozoa.... do you think I need a higher flow or is your 300goh working well still for you? Any concerns about pods getting nuked at that flow?

Gotcha! Ya, my return does up to 2000 gph but since I'm branching off the return, the UV is only getting about 300-400 right now. I've had algae issues. Mostly just green buildup, not really GHA or bubble, just slime occasionally. Nitrates are kept under 10 so the algae isn't getting too out of control. I know ich was in my tank at one point so I have to keep my UV flow pretty slow for that reason.

I wouldn't worry too much about pods. Generally, you can keep an eye on population by looking for them. I don't have experience with 100% of the return water going through UV but if it's going to affect pods, obviously that's the scenario where you will see the biggest impact. With my UV branching from return my pod population is still booming.