UV sterilizer setup, is 3/4 in hose really enough?

[Cramtechnician]

I am in the early stages of getting to 220 gallon peninsula tank setup and just received my UV sterilizer. I thought the 2 inch fittings would be able to be used but adapters have been glued in already with 3/4 inch barb fittings.

This is a 40W Aqua Ultraviolet unit, they say for reef applications you want at least 1900 gph through this unit. If this is the case why glue in 3/4 inch fittings? Can you really flow that much through a 3/4 inch fitting? Does anyone know if you can just get a 2" union schedule 80 union and thread it onto here?

This is being installed via manifold setup coming from a reef octopus various 8 pump.

 

[mcarroll]

If you are doing a cheapie manifold installation instead of a real deal installation, I think the low flow is fine. You're only gonna be targeting algae and nothing else.

But if you are targeting parasites and bigger nasties like dinoflagellates, then you would want to install it on your main return line to process all of the tanks flow.... I'm not sure, but you might need a larger unit for that.

As for the questions about sizing and the fittings, I would direct those towards the maker. Give them a call.

 

[UncommonSense]

This is a 40W Aqua Ultraviolet unit, they say for reef applications you want at least 1900 gph through this unit. If this is the case why glue in 3/4 inch fittings?

I assume this is a classic series unit; if so, the numbers definitely don’t add up, and this should absolutely be sold with a minimum of 1” barbed fittings… I see your concern…

From Aqua UV’s site:

967gph is more or less terminal velocity through the ~5/8” ID of a 3/4” barbed fitting… you’d need a beefy pump feeding it to even hit that flow number after all the restriction…

Do you plan to plumb this UV directly on the return for waterborne parasite control?

If so, it’s actually a bit undersized for the tank size! (You typically want to run near the minimum UV flow rate for maximum UV dosage on any given sample of water)


— Do you plan you use this particular UV still? If so, there are replacement 2’ union halves!

If you plan to switch to a higher wattage model for a plumbing configuration where all water returned to the display gets sterilized thoroughly, I’d recommend ordering it with the 2” unions only, not with any barbed fittings pre-glued!

 

[Jamie814]

Does anyone know if you can just get a 2" union schedule 80 union and thread it onto here?

You would just need 2 of these to replace the 3/4" glued fittings,

Union Female Half with Nut 2" Black - Aqua UV

 

[Cramtechnician]

Does anyone know if you can just get a 2" union schedule 80 union and thread it onto here?

You would just need 2 of these to replace the 3/4" glued fittings,

Union Female Half with Nut 2" Black - Aqua UV

Thank you! This is exactly what I was looking for. Yes I do plan on having most of the water flow through the UV. Going to use a flow meter and keep it around 1900 gph with the rest bypassing in the manifold setup.

 

[Cramtechnician]

This is a 40W Aqua Ultraviolet unit, they say for reef applications you want at least 1900 gph through this unit. If this is the case why glue in 3/4 inch fittings?

I assume this is a classic series unit; if so, the numbers definitely don’t add up, and this should absolutely be sold with a minimum of 1” barbed fittings… I see your concern…

From Aqua UV’s site:

967gph is more or less terminal velocity through the ~5/8” ID of a 3/4” barbed fitting… you’d need a beefy pump feeding it to even hit that flow number after all the restriction…

Do you plan to plumb this UV directly on the return for waterborne parasite control?

If so, it’s actually a bit undersized for the tank size! (You typically want to run near the minimum UV flow rate for maximum UV dosage on any given sample of water)


— Do you plan you use this particular UV still? If so, there are replacement 2’ union halves!

If you plan to switch to a higher wattage model for a plumbing configuration where all water returned to the display gets sterilized thoroughly, I’d recommend ordering it with the 2” unions only, not with any barbed fittings pre-glued!

Yes is it the classic series. The site I ordered from had it on sale but I couldn’t tell if the 3/4 in fittings were optional or not. Turns out they are preinstalled from whatever reason.

I am running the sterilizer on a manifold with a flow meter so that I can target parasites if needed by slowing the flow, typical operation will just be for algae control and water clarity so higher flow. Turn out aqua cave sells the 2” fitting by themselves so I will go that route for now.

As far as size goes the manufacturer says this is good up to 330 gallon reefs, I figured that would be enough for my 220. What would the benefit be for going larger? Do the manufacturers just severely overrate their equipment? I do notice a lot of people on here run sterilizers that are much larger.

 

[UncommonSense]

Turn out aqua cave sells the 2” fitting by themselves so I will go that route for now.

Perfect!

As far as size goes the manufacturer says this is good up to 330 gallon reefs, I figured that would be enough for my 220. What would the benefit be for going larger? Do the manufacturers just severely overrate their equipment? I do notice a lot of people on here run sterilizers that are much larger.

The manufacturer rates these UV sterilizers accurately, “up to 330G” implies that is the dead max it can handle! — this UV would be doing around 3x turnovers per-hour if hooked up in-line on return plumbing, and run at minimum flow rate for parasite control (967gph)!

This sterilizer is hitting just shy of 5x turnovers per-hour in your 220g tank, if plumbed as above! — this is plenty, though some users want to increase that turnover number further… it’s entirely up to you, based on the math that you end up running for your system’s flow needs!

 

[Cramtechnician]

Turn out aqua cave sells the 2” fitting by themselves so I will go that route for now.

Perfect!

As far as size goes the manufacturer says this is good up to 330 gallon reefs, I figured that would be enough for my 220. What would the benefit be for going larger? Do the manufacturers just severely overrate their equipment? I do notice a lot of people on here run sterilizers that are much larger.

The manufacturer rates these UV sterilizers accurately, “up to 330G” implies that is the dead max it can handle! — this UV would be doing around 3x turnovers per-hour if hooked up in-line on return plumbing, and run at minimum flow rate for parasite control (967gph)!

This sterilizer is hitting just shy of 5x turnovers per-hour in your 220g tank, if plumbed as above! — this is plenty, though some users want to increase that turnover number further… it’s entirely up to you, based on the math that you end up running for your system’s flow needs!

Awesome, thanks a ton for the thorough replies! I’m excited to get back into the hobby after 12 years off. Great to run across such an active and helpful community!

 

[mcarroll]

Yes is it the classic series. The site I ordered from had it on sale but I couldn’t tell if the 3/4 in fittings were optional or not. Turns out they are preinstalled from whatever reason.

My guess is that unit is targeted toward pond or possibly freshwater people who are purely targeting green water algae. not sure though.

I am running the sterilizer on a manifold with a flow meter so that I can target parasites if needed by slowing the flow, typical operation will just be for algae control and water clarity so higher flow. Turn out aqua cave sells the 2” fitting by themselves so I will go that route for now.

If targeting parasites is seriously one of your priorities, then it needs to be plumbed in line directly to carry 100% of the flow from the sump to the tank. You will lose the battle numerically against parasite swimmers if you use a bypass. (they reproduce very quickly, and it only takes a few to get them started.)

that doesn't mean you have to operate it 100% of the time

As far as size goes the manufacturer says this is good up to 330 gallon reefs, I figured that would be enough for my 220. What would the benefit be for going larger? Do the manufacturers just severely overrate their equipment? I do notice a lot of people on here run sterilizers that are much larger.

If you've seen the sizing guide on AquaUV's website, then you know how the sizes range based on the tank and the intention.

According to that chart you can take this unit to 2900 GPH and still treat algae. That's a lot of flow.

If you're targeting parasites, that needs to come down to about 900 GPH.

A 220 gallon tank needs no more than 220 GPH through the filter section, so the UV is quite oversized from that stanard. You could return this unit and go with a smaller unit like a Classic 15 or Advantage 2000+.

But you might elect to use 2x-4x that flow rate, so possibly 500-900 GPH if you need flow on the high side for some reason. In that case, it seems like the Classic 40 will carry 100% of your flow. You just need the replacement endcaps, and *not* to plumb it manifold style. Put it straight inline with your return. IMO run it "as needed". Once the fish population is settled and peaceful, you might find little need for it.....until next time you add fish. So run it for the first X months. Then leave the bulbs off. When the next time comes, you can *carefully* clean the quartz tubes if needed, and then get the remaining X months of usage still remaining on the UV bulb. (It's not a pond, so unlikely you'll need year-round protection from algae. So having ti "off" most of the time could be the norm once the tank is mature.)

 

[mcarroll]

Oh! Worth pointing out that if you run it for parasites, you're at the lowest SAFE flow rate for the unit before overheating can become an issue.

IMO use actual measurements of flow to determine your system's flow rate. Measure (eg) drain flow with a convenient container and a stopwatch and calculate actual GPH.

 

[Jamie814]

Going to use a flow meter and keep it around 1900 gph with the rest bypassing in the manifold setup.

Just an FYI, flow meters can be highly inaccurate and high maintenance. Once they get a bit of buildup, algae, or a piece of debris caught in them they tend to give incorrect readings. They also add more backpressure on the pump and restrict flow.

I would search here on R2R and read more about them before installing one.