Aqua UV unit - help with insane flow recommendations

[nkyreef]

I have been researching UV units for my new setup. I have been looking at Pentair and Aqua. At first, I was sold on Pentair and flow rates made sense. Then, I read numerous reviews of failing / melting units, and went to Aqua. Specifically, the 57 Watt unit. Aqua's recommended flow rates for it are a whopping 1,066 - 1,280 GPH for disease, and 2,133 - 3,200 GPH for algae and bacteria. And, the unit comes with 3/4" barbs for in and out. These flow rates are insane and I don't even know how it would be possible with 3/4" tubing. They are very, very different from what Pentair recommends on its unit. You peeps with the Aqua, are you really running that kind of flow? I won't even have a flow meter and was going to do the old milk jug method, fill up a gallon, and calculate it. But at the minimum flow, it's almost 18 gallons a minute. This makes no sense!

We may have the same tank considering your name. I run an Aqua UV 25 watt on my Red Sea 525XL. The only reason I didn’t choose the 57 watt was because of the overall size. My apex flow meter shows a flow of about 460 gph. I contacted Aqua UV when i originally installed it about they're crazy high flow rates. They wouldn't budge from their stated numbers. I picked a flow rate that made sense for my tank and left it at that.

 

[14 foot reef]

Pentair was originally owned by Steve at Emperor Aquatics. He engineered his UV's way different than Aqua-Ultraviolet but since the buy out, the Pentair brand has changed a lot.
Aqua-Ultraviolet advertises a very high number for flow rates ( IMHO ) I dont agree with the kill rate they advertise.
They also 100% do not recommend running UV on a reef tank. So you have to plug that into your thoughts also.
I have found if you go back to the old Emperor Aquatics flow recommendations you will be way more accurate.
If it's any help I run a 200 watt Aqua-Ultraviolet at 1600 gph on a full SPS dominant 850 gallon reef.

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwjLkpuxnZ38AhX5LFkFHQo7CWEQFnoECA4QAQ&url=https%3A%2F%2Fstatic1.squarespace.com%2Fstatic%2F566f4c6cd8af1045cf929178%2Ft%2F59b981362994cad1d328a997%2F1505329467170%2FEmperor%2BAquatics%2BU.V.%2BInstruction%2BManual.pdf&usg=AOvVaw1ksaW8FijeAp5q5ssIuGFE

 

[South Carolina reef]

Question about this. I understand flow rates however one would think that eventually uv will sterilize everything that passes through it over time no? I installed a 15w acqua on my 65 gallon and run it 24x7 through my return pump. Mostly for water clarity and the overall benefits for possible parasites.

 

[mskvarenina]

I have been researching UV units for my new setup. I have been looking at Pentair and Aqua. At first, I was sold on Pentair and flow rates made sense. Then, I read numerous reviews of failing / melting units, and went to Aqua. Specifically, the 57 Watt unit. Aqua's recommended flow rates for it are a whopping 1,066 - 1,280 GPH for disease, and 2,133 - 3,200 GPH for algae and bacteria. And, the unit comes with 3/4" barbs for in and out. These flow rates are insane and I don't even know how it would be possible with 3/4" tubing. They are very, very different from what Pentair recommends on its unit. You peeps with the Aqua, are you really running that kind of flow? I won't even have a flow meter and was going to do the old milk jug method, fill up a gallon, and calculate it. But at the minimum flow, it's almost 18 gallons a minute. This makes no sense!

I spent some time reading through the articles that were linked in this thread, one was a very tough read but simply stated doesn't just make sense that the lower the GPH, the longer dwell time and the better the "kill" or sterilization of the water? I have the 57w Aqua and the manufacturer told me today anything less that 1066 GPH would make the UV ineffective. Why would that be in layman's terms?

 

[Crofty]

I spent some time reading through the articles that were linked in this thread, one was a very tough read but simply stated doesn't just make sense that the lower the GPH, the longer dwell time and the better the "kill" or sterilization of the water? I have the 57w Aqua and the manufacturer told me today anything less that 1066 GPH would make the UV ineffective. Why would that be in layman's terms?

They may be speaking to the need to run all your tank volume through the UV in a given amount of time to effectively kill what you want. A low flow will kill what goes through the UV unit, but will not be as effective overall for the tank as a whole.

 

[XLReefer525]

I gave up trying to make sense of Aqua's numbers. I too contacted them and they stood firm at their recommended flow rates. I bought a Lifegard 55W instead. Totally normal flow rates that I could implement...

 

[Aluco]

+1 for coralife. I have been running one in my tanks for 6 months. I have a 35w on my 120 gallon system and

no issues. Idk how much it's helped but that's kind of the point. I run around 220gph through it, 12 hours a day during nighttime. Fish are squeaky clean though and pest algae only is seen in the back left corner, probably low flow back there..

I know in this sort of discussion only top tier equipment is seen as worth it and my experience is unlikely to change anyone's mind but, I mean it's been a solid piece of equipment for me.

 

[mskvarenina]

They may be speaking to the need to run all your tank volume through the UV in a given amount of time to effectively kill what you want. A low flow will kill what goes through the UV unit, but will not be as effective overall for the tank as a whole.

That's an interesting thought, so the UV is killing what flows through it and maybe Aqua is simply saying 1066 GPH is the minimum required to fully cleans the tank, meaning that a flow rate less than 1066 may not turn over the water enough times per hour to be 100% effective?

Today I'm running about 500 GPH, can't say either way if my UV is working, my fish never have disease so maybe the UV is working, but I do have some nuisance algae.

Think I should bother upgrading my pump to achieve the 1066 GPH requirement?

 

[DCR]

I don't think Aqua UV really understands turnover rates on a tank or hydraulics and I go by Pentair's recommendations for the same wattage. If they seriously expected users to operate with at least 1066 gph of flow, they would not include 3/4" barbs as they are completely incompatible with 1066 gph. I run 40 W units with an estimated 150-200 gph driven with an Iwaki 15R without issue.

 

[Crofty]

Think I should bother upgrading my pump to achieve the 1066 GPH requirement

Having worked with UV sterilization in industrial RODI systems and distribution loops, it makes sense to maximize flow within the limits of your UV to maintain sterility as much as possible. Usually under high pressure which allows for smaller tubing and less residence time for water flowing though the loop.

But for a living aquarium environment that seems like just overkill (and maybe not necessarily desirable). I'm certainly a novice when it comes to UV for aquariums but I'm guessing if 500 gph is a healthy turnover rate for your other aquarium filtration then its probably good enough for your UV to reduce the undesirable bio load to an acceptable level.