UV Sterilizers: Are the benefits a MYTH or a REALITY?

[Belgian Anthias]

Using UV-C, I think the benefits may be a myth as well they are a fact.

UV_C when correctly used will sterilize the water passing true the unit. If not used correctly UV-C will sterilize the water partially and leave difficult pathogens behind favorizing them in the ongoing competition.

UV-C will not sterilize the tank as space and nutrients not taken by ancestors of sterilized organisms will rapidly be taken by organisms present in the tank or and by organisms spared due to a too low dose.

UV-C is very effective to sterilize the water to be used in a quarantine tank and to lower the pathogen pressure.
UV-C germicidal units must be used correctly and doses must be high enough to kill all marine pathogens, otherwise, the cure may be worse as the disease. As such units often operate at a low flow rate the temperature of the water in the unit may rise above 40°C. This means such a unit can not be connected directly to the tank. To prevent too high temp the unit must be big enough. Good UV-C germicidal units are big and expensive. For smaller units use amalgam UV-C germicidal lamps!

Using a good UV-C unit with water coming from the skimmer will prevent the selective removal of TOC by the skimmer may favor the development of pathogens or and certain kinds of bacteria not skimmed.

Using UV-C at low doses just to battle photo-autotrophs is a very bad idea.

If UV-C germicidal units are used they must be able to sterilize the treated water, if not, please do not use them!

 

[Xero]

Using UV-C, I think the benefits may be a myth as well they are a fact.

UV_C when correctly used will sterilize the water passing true the unit. If not used correctly UV-C will sterilize the water partially and leave difficult pathogens behind favorizing them in the ongoing competition.

UV-C will not sterilize the tank as space and nutrients not taken by ancestors of sterilized organisms will rapidly be taken by organisms present in the tank or and by organisms spared due to a too low dose.

UV-C is very effective to sterilize the water to be used in a quarantine tank and to lower the pathogen pressure.
UV-C germicidal units must be used correctly and doses must be high enough to kill all marine pathogens, otherwise, the cure may be worse as the disease. As such units often operate at a low flow rate the temperature of the water in the unit may rise above 40°C. This means such a unit can not be connected directly to the tank. To prevent too high temp the unit must be big enough. Good UV-C germicidal units are big and expensive. For smaller units use amalgam UV-C germicidal lamps!

Using a good UV-C unit with water coming from the skimmer will prevent the selective removal of TOC by the skimmer may favor the development of pathogens or and certain kinds of bacteria not skimmed.

Using UV-C at low doses just to battle photo-autotrophs is a very bad idea.

If UV-C germicidal units are used they must be able to sterilize the treated water, if not, please do not use them!

i think it's behind some kind of subscription/paywall, but I think this follows along with some of what I had talked about in some other groups yesterday, with regards to exposure times and the fact that unless you're targetting 336,000uw/cm2, and possibly even up to 800,000uw/cm2 of exposure time, you are likely not killing autotrophs, rather, just beefing them up like this article says.

I actually do run a UV on two of my three quarantine tanks. Especially after learning copper power is mostly safe with UV (it's cupramine that's not...)

I usually suggest the opposite regarding the skimmer - having the output of the UV go to the sock or skimmer chamber, so that it picks up the dead stuff, as opposed to feeding the uv with the skimmer?? I'm not even sure how that's possible in normal practice, is this lost in translation???

 

[Xero]

Aqua Ultraviolet
15 Watt Classic UV Sterilizer
What is the minimum flow rate for this unit?

If you want it to be effective at parasite control, that unit is good up to 50g at 50gph....

 

[Belgian Anthias]

I usually suggest the opposite regarding the skimmer - having the output of the UV go to the sock or skimmer chamber, so that it picks up the dead stuff, as opposed to feeding the uv with the skimmer?? I'm not even sure how that's possible in normal practice, is this lost in translation???

A skimmer is very selective for removing TOC, leaving most bacteria ( +- 65%) and the same kind of bacteria behind. Wich means some bacteria are favored. This may influence and change normal evolution in the tank in the long term.

That is why my advise is if UV-C is used on a reef tank to connect it to the outflow of the skimmer or make use of skimmed water. This way the skimmer can not favor pathogens or sorts of bacteria present in the water column.
The other way around and sterilized water is fed to the skimmer, of course, the skimmer can not favorize live forms anymore and maybe more TOC and DOC can be removed? I have no clue in what way UV-C may change polarity and as UV-C damages DNA but does not immediately kill I doubt if a skimmer will perform any better. I have only one argument for doing it my way, the fact the UV-C will be fed by cleaner water and its effectiveness will be increased if fed by the skimmer output. If a skimmer performs better with UV-C treated water I certainly may follow the advice for using sterilized water to feed the skimmer as the flow rate of a good UV-C unit which is powerful enough can be adjusted easily to the needs.

As one may use refugia, everything is easily manageable.

If UV-C is used it is everything or nothing. Selective use of UV-C is not advisable as the cure may be worse as the disease!
As benthic organisms are not affected at all, I do not advise to use UV-C, as I advise not to use a skimmer, if it is avoidable. But a good UV-C unit is very effective to sterilize used or natural seawater if it is needed.
If a skimmer is used, and who doesn't, the use of a good UV-C unit in combination can be advised.

 

[Doostur]

I added one because I had an empty slot on my manifold. I had no real issues requiring one. Figured why not. I predict im running about 400 GPH. Aqua 57w. Had to run it at night time where my AC temps are lower because it was causing my temps to rise by about 1 degree.

I have noticed no positives or negatives after 3 weeks.

 

[Lowell Lemon]

In the old days we ran UV after mechanical filtration to boost the performance. The clearer the water the more effective the UV.

 

[madweazl]

Hasn't affected tank temps for me but the sump is in the basement which is fairly cool year round anyways. Pentair 40w was installed March 14.

 

[Drew Halliday]

Here’s a photo from the Aqua UV website. The slower the flow rate the more planktonic food supply for the reef gets destroyed. Faster flow rate is ideal for reefs.

If the highest dose kills parasites and a lower dose allows plankton to pass by what is the lower dose good for? helping with algae outbreaks?

 

[RedSea500MaxS]

Here is a little write up I did on UV Sterilizers if anyone is interested.

UV Sterilizers, which to choose and why?

Ever since BRS did a video on UV's and QT I have seen a lot more people talking about UV's. Naturally most purchase what BRS pushes / sells which is fine and dandy (I also love BRS) but I suggest everyone do their research. When selecting the right UV you need to determine what it is that you...

humble.fish

thank you...this is A GREAT POST! Thank you.

 

[RedSea500MaxS]

A big one helps with "management". It doesn't prevent anything, but it does clear some things up. I love the one I have and I loved the one in my last tank. I basically use mine for algae control. But having one doesn't mean you can put off tank maintenance. It is just a tool to help. If I get another tank, I'll be sure a UV sterilizer comes with it.

which UV for algae please.

 

[Spieg]

Don't know and don't really care. My tanks (30+ years of salt water aquariums... man I'm old!) have always been fine without UV so why bother with additional expense, power consumption, plumbing, heat, and maintenance?

 

[scardall]

If you want it to be effective at parasite control, that unit is good up to 50g at 50gph....

at 50gph will it reduce cyno and prevent dino's as well? In truth I would like to an all in one UV setup.

 

[Xero]

at 50gph will it reduce cyno and prevent dino's as well? In truth I would like to an all in one UV setup.

what size tank is it? 50gph on a tank under 50g would give you exposure times of over 360,000uw/cm2 at the rate of 1x turnover per hour. That's enough to kill many things, including possibly ich.

If you want to target algae reduction as well as parasite reduction, you could try to size a larger unit to get you that same exposure at 2x turnover. Like a 25w at 100gph, a 40w at 200gph, 57w around 250gph, and so on.....all these would be hitting that 360k number at those flow rates, but what that turnover rate is will be your tank size divided by the GPH....

All this is going on the assumption you need 300k to 800k to kill ich, and that these manufacturers are majorly short-changing us in regards to what parasite reduction really means.

 

[Belgian Anthias]

at 50gph will it reduce cyno and prevent dino's as well? In truth I would like to an all in one UV setup.

A good UV-C unit only sterilizes the water passing true it, It does influence what is happening in the tank but cyano and or dino growth may as well increase as decrease because by using an UV-C one is removing competition. As a good UV-C unit must be able to kill everything it also kills dino's and cyano's present in the water column. You must look at the UV lamp used and its specs and the flow must allow at least 225 000 µW-s/cm². If you do not know the specs of the lamp used in the unit then you better do not use it.

 

[Salty Lemon]

which UV for algae please.

With this you need research. It all depends on your tank size, finances, and what works best for you. I have a Coralife Turbo-Twist. I bought it from my LFS because I try to purchase locally as much as possible. They only carried a few brands and that was the one I chose. But that is just me. So far I have been happy with it. Here are a few links to get you started. I hope this helps.

The Best UV Sterilizers For Aquariums of 2023

Find out which UV sterilizer is best for your aquarium. We cover the top 7 best aquarium UV sterilizers available on the market today.

aquariumadviser.com

UV sterilization

I have noticed that UV sterilization is often a subject of wonder or uncertainty. I personally have one unit on my largest of four tanks. What is a UV Sterilizer? It is a process using ultra violet (UV) light for capturing and making sterile...

www.reef2reef.com

A UV Sterilizer For a Reef Tank? - ReefBum

Reef keepers have long debated whether the constant use of a UV sterilizer is helpful or harmful to a saltwater reef tank.

reefbum.com

How to Choose an Aquarium UV Sterilizer: The 5 Best Reviewed

Check out our review of the 5 best aquarium UV sterilizers. Learn how UV sterilizers work and how to choose the right one for your fish tank.

www.fishtankworld.com

 

[JCOLE]

I use one and swear by it. I have it tied into my apex controller and run it during overnight hours only( 11 hours per day). My question to the group is how long per day do you run your UV Sterlizer?

This is the same way I do it. My Apex turns it on from 12am to 12pm.

 

[Charlie C]

My experience is that disease outbreaks are less severe when they happen and that they happen less often with a UV. I don’t think I’d ever run a tank without one.

 

[Charlie C]

I use one and swear by it. I have it tied into my apex controller and run it during overnight hours only( 11 hours per day). My question to the group is how long per day do you run your UV Sterlizer?

24/7 for me, but I don’t keep corals currently. I plan on adding corals later this year so will have to consider that. But I would not run a tank without a UV, at least part of the time.

 

[RedSea500MaxS]

Ok, I am overwhelmed.

Not worried about ick but........to control algae and good water clarity for my 165 gal mixed reef....which UV is best bang for the buck and long term reliability?

Advantage if it works well with my Apex.

 

[Belgian Anthias]

My experience is that disease outbreaks are less severe when they happen and that they happen less often with a UV. I don’t think I’d ever run a tank without one.

How can you know,? Compared to what? It may be the opposite for certain diseases as you may favor them by removing competition, certainly if the dose used isn't high enough as often is the case in practice.