UV Overkill or nay?

[JPSika08]

I have a 150Watt Emperor Aquatics Smart HO UV, I used it for my former system which had around 1200 Gallons. I was considering using it form y 300 Gallon system, would that be overkill? Maybe use it during certain hours per day?

I still have to measure the thing to be able to fit under my tank.

TY.

 

[FarmerTy]

Other than the extraneous replacement of bulbs, I don't see any issue with it. Can you just run less bulbs in the unit?

 

[JPSika08]

Other than the extraneous replacement of bulbs, I don't see any issue with it. Can you just run less bulbs in the unit?

This unit uses only one bulb, pretty big, but just one, I think leaving it 24/7 will last about an year, but if I use it 4 hours per day its life would be longer.

 

[FarmerTy]

JPSika08,

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.

 

[JPSika08]

JPSika08,

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.

Thank you very much for this great post!, The tank's GPH right now is around 5x or so. I was planning on placing this UV on the return pipe with a middle Ball-Valve so I can control how much flow will go though it, being setup like this I can control the turnover much easier.

As of now I don't have any Crypto in the tank (At least I think so), I just finished cycling, the only livestock in there right now is an Emerald Crab I introduced today; My plan is to have a good QT procedure.

My main reasons to setup this UV,
1. Would like to have my water in pristine conditions and the UV will achieve that.
2. In case a Crypto problem breaks out, I know that with this thing I can manage the population pretty well due to it's size.

I really don't know if these are the correct reasons to actually set it up.

 

[FarmerTy]

Personally, I don't think it will hurt so I would run it 24/7 with a bulb change at 14 months, as I believe that is what AquaUV bulbs are rated for.

It will definitely help polish the water and in case crypto does break out, it will keep it from being a tank wide issue. You are taking a good step in secure QT procedures being the first line of defense though. TTM is amazing for ich and such a simple process.

 

[JPSika08]

Thank you very much, I'm planning to go with TTM for QT, here are my actual tanks for doing this,



And the bigger QT is getting cycled:


I will set my UV, thank you very much for all your great feedback! I will place some pics over my thread and here to keep continuance.

 

[FarmerTy]

Very nice QT setup! Try to resist prepping the next tank too early due to the possible aerial transmission of ich. I usually fill it up with RO/DI water, set up the filter, and then drop in the heater to stabilize temps. I won't add salt to it until an hour before I am actually going to do the transfer.

 

[JPSika08]

Very nice QT setup! Try to resist prepping the next tank too early due to the possible aerial transmission of ich. I usually fill it up with RO/DI water, set up the filter, and then drop in the heater to stabilize temps. I won't add salt to it until an hour before I am actually going to do the transfer.

Thank you, do you use new water for the TTM or DT water?

I will get the rest of the equipment today. (Filter and heaters).

 

[FarmerTy]

Depends how much you trust the DT. If you're 100% sure its clean, then use the DT water. If not, I would use fresh.

I personally don't do water changes on my DT so I don't mess with that water when possible, even to borrow water for a QT.

 

[JPSika08]

I think I'll go with fresh water instead, much easier/safer.

Thank you for all your help.

 

[FarmerTy]

I think I'll go with fresh water instead, much easier/safer.

Thank you for all your help.

You're very welcome. [emoji106]

 

[Oceansize]

I've read that 5W UV is insufficient for saltwater tanks larger than 40 gallons. Personally I'm using 9W for 75 gallons, and am pleased with the results, although I wouldn't mind more wattage. Extrapolating from those standards, you're definitely not in danger of having too much UV.

My objective is not necessarily the prevention of ich (I have finished stocking the fish in my tank without any disease, doubtful that an outbreak would happen now if I'm not adding any more stock); my purpose for using UV is reduction of algae, and on that point my UV absolutely meets my needs.

 

[FarmerTy]

I've read that 5W UV is insufficient for saltwater tanks larger than 40 gallons. Personally I'm using 9W for 75 gallons, and am pleased with the results, although I wouldn't mind more wattage. Extrapolating from those standards, you're definitely not in danger of having too much UV.

My objective is not necessarily the prevention of ich (I have finished stocking the fish in my tank without any disease, doubtful that an outbreak would happen now if I'm not adding any more stock); my purpose for using UV is reduction of algae, and on that point my UV absolutely meets my needs.

Sounds about right, you hardly need much for it to be used as a clarifier of algae only.

 

[brandon429]

there is no overkill for UV on reefs, only underkill

I once ran a pond sterilizer for a ten thousand gallon koi pond on my 75 gallon planted tank, wonderful cheat.

the good things we zap with them in reefkeeping are incidental, and if they were critical we wouldn't need to be feeding tanks only the planktors would be needed

if someone has a cryptic zone setup, that might contraindicate a UV sterilizer

how rare are those, 2004 called heh

sorry to offend the single cryptic reefer on here if applicable heh they are neat bio zones

 

[Randy Holmes-Farley Verified Community Expert]

A drawback to UV for some folks is the killing of bacteria. I dosed organic carbon for years to increase bacterial growth, and I'd prefer those bacteria in the water column to remain alive until skimmed or eaten by filter feeders, rather than being killed and spilling their guts back into the tank warer.

 

[brandon429]

yep carbon dosers beware

another time I wouldn't use them for clear reasons would be the live phyto setups, rare but golden tanks for sure. I never found any chemical impacts from gross overburning though, that was neat. the system was just cheated clean when otherwise id need to take care of it to be cyano free

which salt to use and UV/No uv are the oldest debates in reefing. some reefcentral threads back in the day ran 400 pages all hashing is renewal of those old fun posts