Aqua UV Sterilizer Question

[OnPointCorals Verified Sponsor]

I am looking at the classic 25 watt & 57 watt.

I see for the 25 watt:
90,000 µw/cm2 (EOL) requires 400 gph flow

for the 57 watt:
90,000 µw/cm2 (EOL) requires 1066 gph flow

I have around a 150 gallon total water volume so in theory either model will suffice. Is it apple to apples as far as sterilize power if I run the 25 watt at above flow and the 57 watt at above flow?

 

[TinyChocobo]

You can always go lower on the flow but if you go higher - things will move past the UV too fast for it to be effective. Their site does list how effective it is at various flow rates.

I am personally looking at the 25 Watt myself and was probably going to do something like 250GPH.

 

[OnPointCorals Verified Sponsor]

Thanks. Can anyone else weigh in on the original post?

 

[neupane00]

What’s the goal ? Clear water or disinfect ? If just looking to clarify 25 is enough. When I had 180 tank I used to have 57w

 

[TinyChocobo]

Personally I want a UV for both reasons . Not sure about @addictreef

I planned on putting my UV in-line between my pump and my algae reactor so that it's sump -> UV -> reactor -> sump .

 

[Reefer1978]

I am running 57w on Reefer 425xl. It's inline into the return line, all water passes through it. Tank is nice and clean.

 

[OnPointCorals Verified Sponsor]

Thanks for all the responses. Yes I would like the uv for both reasons myself.

I would like an answer to my question above though. Will the two examples I presented have the exact same kill rate?

 

[FarmerTy]

You'll want the 57-watt for sterilizing. Yes, you can run a slower flow to maximize kill rate but that reduces the total volume of water that runs through the unit per hour. You desire around 3x turnover/hour to be most effective at sterilization so slowing the flow too much will give you an ineffective turnover/hour despite your kill rate flow being perfect.

 

[OnPointCorals Verified Sponsor]

You'll want the 57-watt for sterilizing. Yes, you can run a slower flow to maximize kill rate but that reduces the total volume of water that runs through the unit per hour. You desire around 3x turnover/hour to be most effective at sterilization so slowing the flow too much will give you an ineffective turnover/hour despite your kill rate flow being perfect.

Thank you. This is what I was looking for. If in fact I want 3x turn over an hour: I have 140 total water volume 140x3 = 420?

So what that said wouldn’t the 25 watt be just about sufficient for both?

Obviously the more turn over an hour the better.

 

[TinyChocobo]

I am running 57w on Reefer 425xl. It's inline into the return line, all water passes through it. Tank is nice and clean.

Did you find it slowed your return rate much or at all? I was looking at adding it in-line on my return although I do have a separate reactor pump I can run it off of so that I can dial in the speed as desired without adjusting the return / overflow.

 

[TinyChocobo]

25 Watt will likely work fine, 57 watt is more 'future proof' should you up your flow from the return pump.

 

[Oberst Oswald]

Get the biggest and best UV you can afford. If it can prevent dinos from ever occurring it will be the best money you ever spent for your reef.

 

[OnPointCorals Verified Sponsor]

Did you find it slowed your return rate much or at all? I was looking at adding it in-line on my return although I do have a separate reactor pump I can run it off of so that I can dial in the speed as desired without adjusting the return / overflow.

I originally had my 25 watt off a manifold from my return pump I found it difficult to dial in the flow. I now run it off of a sicce pump solely for the UV and feel better that I know what rate it is getting.

The reason I originally posted this is I was wondering if upgrading my 25watt Aqua uv would be worth the cost.

 

[OnPointCorals Verified Sponsor]

Get the biggest and best UV you can afford. If it can prevent dinos from ever occurring it will be the best money you ever spent for your reef.

I initially bought it for Dinos and It did the trick running directly in the display tank.

 

[FarmerTy]

Thank you. This is what I was looking for. If in fact I want 3x turn over an hour: I have 140 total water volume 140x3 = 420?

So what that said wouldn’t the 25 watt be just about sufficient for both?

Obviously the more turn over an hour the better.

The answer is slightly deeper than that. We have to go over ideal kill rate for the sterilizer for marine protists as most are concerned with ich for sterilization purposes. For clarification, the 25 watt would work all day.

Perhaps I could point you to another thread I contributed as today is a busy day at work and I don't have enough time to explain it as clearly as I would hope to.

Here is an except I copied from it and also the link to the thread. I was responding to a reefer about his current setup. Please also keep in mind that in my own experiences, when I hooked up my UV to my manifold in my sump, I had marginal results. Its only when I hooked it up to pull water directly from the lower portions of the display, fed it into the sterilizer, and back into the display, did I have the best success. My theory is the free swimming trophonts tend to stay towards the lower portions of the water column and most don't get high enough to spill over the overflow and into the sump to be irradiated. So having your UV in the sump hooked up to your manifold is almost useless IMO. This was backed up with me being able to keep my powder blue tang in my sump ich free for months but the minute I moved it into the display above, it got ich immediately and succumbed to it. The UV in the sump was effective to keep him free of ich but when I moved him to the DT, it was ineffective. Hope the info helps.

https://www.reef2reef.com/threads/uv-overkill-or-nay.245079/

"You have a 150-watt HO Emperor you plan to use on a 300-gallon total water volume tank. Emperor suggests for killing marine protists (ich), you would need an exposure of 180,000 µWsec/cm2 running at 840 GPH to do that.

According to research by the University of Florida:

https://edis.ifas.ufl.edu/fa164

"Use of ultraviolet (UV) sterilization to kill theronts has been suggested, based on research involving Ichthyophthirius multifiliis (freshwater "ich"). The recommended UV dose for Ichthyophthirius theronts is 100,000 µWsec/cm2 (Hoffman 1974). However, UV doses required for Cryptocaryon irritans are anecdotal or extrapolated, and range from 280,000 µWsec/cm2 (industry numbers) to 800,000 µWsec/cm2(Colorni and Burgess 1997)."

So the extrapolated saltwater ich exposure needed to kill it with UV is anywhere from 280,000 to 800,000 µWsec/cm2. I've run with 336,000 µWsec/cm2 because I pulled that from a chart I saw many years ago for an exposure level to kill marine ich.

So to adjust Emperor's GPH from the 840 GPH needed for 180,000 µWsec/cm2 exposure to almost double the exposure suggested at 336,000 µWsec/cm2:

336,000 µWsec/cm2 ÷ 180,000 µWsec/cm2 = 1.87
840 GPH ÷ 1.87 = ~450 GPH

Running your UV at 450 GPH will effectively kill marine ich protists going through your 150-watt UV unit. The problem is most recommend at least a 3x turnover per hour for UV to be effective. Basically, the 450 GPH will kill any ich that goes through your UV, but if you don't have it turn over the tank volume at least 3x/hour, you're not killing enough of them to make a true impact to the population. For 3x turnover of your 300-gallon system, you need at least 900 GPH. So effectively, believe it or not, your unit is actually half the size it needs to be for your system as you're only running 450 GPH through it.

Again, these aren't hard rules of thumb. The 3x turnover is not a hard rule, just a suggested rule. The 280,000 µWsec/cm2 - 800,000 µWsec/cm2 extrapolated marine ich exposure value is not a hard line either, especially since it's just extrapolated from a freshwater ich exposure dose.

I just wanted to do the calculation for you to let you know where you stand and to give you comparison to suggested industry rules-of-thumb. Your own application and your intended purpose will help you decide what you really need to do. Just trying to help out a fellow hobbyist."

 

[TinyChocobo]

I originally had my 25 watt off a manifold from my return pump I found it difficult to dial in the flow. I now run it off of a sicce pump solely for the UV and feel better that I know what rate it is getting.

If I put one on my return - I'm going to run 100% of my return through it and would probably be going with a 57 Watt instead of a 25 Watt for my Total Volume of 112, DT of 88G.

If I run it in-line with my reactor(s) I'll go with the 25Watt as the flow will be much slower through the unit.

The reason I originally posted this is I was wondering if upgrading my 25watt Aqua uv would be worth the cost.

It's always best to go with as much as you can get when it comes to UV I think - it allows more flow with the same killing power, or slower flow with substantially more killing power.

I initially bought it for Dinos and It did the trick running directly in the display tank.

That's good! .

If you do decide to upgrade your 25Watt to a 57 or higher - drop me a message as I may buy your 25Watt off you to put in-line with my reactor .

 

[TinyChocobo]

Rough math - if I run the 57 Watt on my reactor line - I'll get ~360,000 µWsec/cm2 exposure as it's running 250 G/hour. This is approximately 2.23X turnover per hour of the total water volume and 2.84X turnover per hour of the display volume.

My return pump is turning the tank over at about ~700 G/hour and then my reactor is pulling water from the sump and putting it back in the sump - in short - I think the 57 Watt would likely kill just about anything that passed through it at the flow I'm running to my reactor and I think my total turnover for the reactor line as well as the sump itself are good enough that I think I would get good treatment of all of the water.

With a 25 Watt in my reactor line I would get a little less than half the dosage I'd guess around ~160,000 - so not 'enough' if I were to be trying to kill ich according to @FarmerTy.

 

[TinyChocobo]

I just double checked my reactor pump line by pulling the end out of the sump and having it fill a gallon jug - looks like I'm only running 150 GPH so only ~1.33 turn-over per hour.

Looks like I may want to get a more powerful pump .

At 150 GPH the 25Watt would be ~240,000 µWsec/cm2 and the 57 Watt would be 639,600 µWsec/cm2 according to my math.

If I go with the 57 myself - I'll more than likely get a more powerful pump and up my flow to ~250 GPH .

 

[schooncw]

I just came across this thread.....I have been in research mode for the last few days and have decided on the Aqua UV 25 watt for my 120 but not sure to go with the wiper or not-opinions?-I spoke to them and was told 350-400 gph is good for max effectiveness. I always thought the flow should be slower but I stand corrected. On other opinions out there regarding flow rate?

 

[Oberst Oswald]

Do not get the wiper. I could be wrong (not often) but when you use the wiper it could scratch the quartz glass tube if there were anything hard on them. On flow I went the slow flow way and worked fine for me on my dino outbreak.