# Should I use a UV sterilizer with EI dosing?



## PBM3000 (7 Aug 2017)

I've been running a Vecton UV steriliser with my main tank for well over a year now without issue - and it seems to have prevented any outbreaks.

I am beginning to EI dose now though and I've read all sorts of conflicting opinion on whether UV should be used with EI dosing.  Most seem to suggest that it causes Iron to 'precipitate' (or something).  Does it cause anything else to break down?

What I've done, in the interim, is to only run it for 9hrs a day between midnight and 9am rather than the 24/7 I used to.

Any guideance?


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## ian_m (8 Aug 2017)

No. The UV will degrade the micros.

So turn it off for 24 hours after micro dosing.

Why are you using UV ? Very few people use it here as not really necessary if things are under control and balanced.


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## PBM3000 (8 Aug 2017)

The reason I use the UV is, well, because 'internet' I suppose. As a rookie I bought one due to the claims that it helped prevent outbreaks and kept the water clear. I might not be running one now with hindsight and a bit of experience. The reason I'm reluctant to stop using it is due to the fact that it's set up on the filter loop. If I were to turn it off for any length of time, would the glass on the lamp not get covered in algae; reducing its effectiveness? 

I'd be happy to turn it off permanently if I was confident it would be effective again when needed and not start an issue now. 

Looking forward to replies for and against.


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## Zeus. (8 Aug 2017)

The glass is normally pretty easy to clean, just dismantle the UV filter on filter clean up day.


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## PBM3000 (8 Aug 2017)

Thanks. It normally would be but the unit is in a really awkward position and I need to dismantle the hoses, remove from the cabinet then unscrew the enclosure, clean the parts, re-seal, reassemble then replace in the cabinet then re-fit the hoses. Not an easy or quick job!

I'm leaning towards just getting rid...
.


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## PBM3000 (5 Sep 2017)

...which I did.  

A month-on and not one jot of difference to the tank.  I've also saved money and energy. 
.


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## FISHnLAB (20 Oct 2022)

ian_m said:


> No. The UV will degrade the micros.
> 
> So turn it off for 24 hours after micro dosing.
> 
> Why are you using UV ? Very few people use it here as not really necessary if things are under control and balanced.


People with wildlife, or introducing wildlife to their tanks may want to use it to help control Mycobacteria in the water column. As per Diana Walstad's research, doing so can help prevent issues and illnesses with one's wildlife due to Mycobacteriosis and other issues.

Also, a good preventative measure or quick fix for green water algae.

No idea about UV's effects on micros but, considering it's benefits, one may want to look into a way to dose while using UV in their system. If anyone knows more about this, I am interested...


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## three-fingers (21 Oct 2022)

UV can be beneficial in a few ways when set up with the correct wattage and flow rate for it's intended purposes. I like to use it on fish tanks I consider heavily stocked, when adding new fish or if I have a fish that had/has an uknown disease. With a high enough wattage and a low flow rate over the bulb (but still a high enough flow rate for the voume of tank), it destroys a lot of pathogens and just bacteria/organic molecues in general. This can make the water seem slightlly clearer too - though good mechanical filteration if more effective long term, and chemical filtration like carbon is more effective at removing organic molecules short-term. Lower powered UV units can be useful for getting rid of green water quickly, but are not much use for anything the rest of the time. I like this article for specific flow-rate/wattage/volume details for your desired results.

Since it does effect chelators used in micro mixes, and in some cases people see iron deficienies when using UV, for most skipping UV and focusing on healthy plant growth is better. Healthy plant growth is more beneficial than UV overall for fish health anyway and certianly better value for money (no UV bulb to power, no wasted chelated ferts - which could be very expensive if your buying branded liquid ferts).

I currently use my UV unit on my planted goldfish tank, and everything is growing very fast with no deficiencies. I dont really like adding medications to the water if possible and I think the UV helped a lot preventing any visble infection with some very bad tail damage one of my goldfish sadly experienced recently. It healed fast 😊. I don't bother turning off the UV unit anymore but I do dose cheap DIY micros nearly every day with a small water change, I dont mind that some EDTA is wasted by running UV. If I was dosing expensive ADA ferts for some strange reason I would turn the UV off lol. It can also break down medications so I would turn it off if I _had _to use chemicals for treating something, it can't be used in combination.

For my messy, clumsy goldfish currently in a 170l  think it's worth the ~10w for the bulb+ tiny pump. For the average planted tank it would be a waste of electricity and extra faff IMO.


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## FISHnLAB (21 Oct 2022)

three-fingers said:


> UV can be beneficial in a few ways when set up with the correct wattage and flow rate for it's intended purposes. I like to use it on fish tanks I consider heavily stocked, when adding new fish or if I have a fish that had/has an uknown disease. With a high enough wattage and a low flow rate over the bulb (but still a high enough flow rate for the voume of tank), it destroys a lot of pathogens and just bacteria/organic molecues in general. This can make the water seem slightlly clearer too - though good mechanical filteration if more effective long term, and chemicical filtration like carbon is more effective at removing organic melecules short-term. Lower powered UV units can be useful for getting rid of green water quickly, but are not much use for anything the rest of the time. I like this article for specific flow-rate/wattage/volume details for your desired results.


Thanks for that Threefingers👍. I too like that site for info and it's where I have been learning about Redox.


three-fingers said:


> Since it does effect chelators used in micro mixes, and in some cases people see iron deficienies when using UV, for most skipping UV and focusing on healthy plant growth is better. Healthy plant growth is more beneficial than UV overall for fish health anyway and certianly better value for money (no UV bulb to power, no wasted chelated ferts - which could be very expensive if your buying branded liquid ferts).


Could one not just dose micros daily and then only run the UV for 4 hours per day 18 hours after dosing? That would give the micros 18 hours to be absorbed and another dose would be added right when the UV turns off for the day. 

Is Fe DTPA still effected by UV? 


three-fingers said:


> I currently use my UV unit on my planted goldfish tank, and everything is growing very fast with no deficiencies. I dont really like adding medications to the water if possible and I think the UV helped a lot preventing any visble infection with some very bad tail damage one of my goldfish sadly experienced recently. It healed fast 😊. I don't bother turning off the UV unit anymore but I do dose cheap DIY micros nearly every day with a small water change, I dont mind that some EDTA is wasted by running UV. If I was dosing expensive ADA ferts for some strange reason I would turn the UV off lol. It can also break down medications so I would turn it off if I _had _to use chemicals for treating something, it can't be used in combination.
> 
> For my messy, clumsy goldfish currently in a 170l  think it's worth the ~10w for the bulb+ tiny pump. For the average planted tank it would be a waste of electricity and extra faff IMO.


Fluval makes a UV Filter that uses a non-replaceable CCFL bulb and an easy to use timer built in. It has a 2 year repair or replacement warranty. What do you think of it? This is what I was planning to add to the output of a Fluval 407 on a 49 gallon tank... 



			https://fluvalaquatics.com/us/product/uvc-in-line-clarifier/


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## three-fingers (21 Oct 2022)

> Could one not just dose micros daily and then only run the UV for 4 hours per day 18 hours after dosing? That would give the micros 18 hours to be absorbed and another dose would be added right when the UV turns off for the day.
> 
> Is Fe DTPA still effected by UV?


You could, I fussed around with timers and dosing at certain times at first, but when my timer settings failed I found it doesnt seem to matter if it was tuned off, as long as if I dosed daily. Turning off the UV for a short time on a very regular basis like that still reduces effectiveness and increases the frequency of cleaning needed as biofilm grows very quickly on the quartz sleeve (and other microbes in the water). When you turn the UV back on they will be killed stuck to the quartz sleeve, or floating in the water, so personally I now think it's best to use it 24/7 if at all.

DTPA is still affected by UV, possibly less so than EDTA (but I'm not sure). If your going as far as using fancier chelators this is maybe be a good reason not to use UV.



> Fluval makes a UV Filter that uses a non-replaceable CCFL bulb and an easy to use timer built in. It has a 2 year repair or replacement warranty. What do you think of it? This is what I was planning to add to the output of a Fluval 407 on a 49 gallon tank...


Hmm, a non-replaceable bulb in 2022 lol. I guess that makes sense for Hagen as they dont make the bulbs so can't sell them directly...our poor planet though. Kinda sceptical about the claim about CCFLs being useful 3x as long as traditional UVC  CFLs too, having used CCFLs in DIY lighting over aquariums before. It's only 3w, and seems to be marketed to fit into an existing external filter loop - which would mean a high flow rate reducing effectivness. Also it's quite compact, and I've not seen the internal design, but I'm guessing dwell time is quite low.

So maybe useful for preventing/clearing greenwater quickly when initially setting up a tank, but a waste of 3w long-term IMO. 3w could be spent on something more useful, like a wavemaker/airpump.

Could be very effective on a nano tank with a tiny filter, and more convenient than larger units.


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## _Maq_ (21 Oct 2022)

FISHnLAB said:


> Is Fe DTPA still effected by UV?


All marketed chelators are _organic_ compounds. As a rule, all organics are more or less subject to degradation when exposed to UV.
The question is whether you actually need _chelated_ micronutrients.


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## FISHnLAB (21 Oct 2022)

three-fingers said:


> You could, I fussed around with timers and dosing at certain times at first, but when my timer settings failed I found it doesnt seem to matter if it was tuned off, as long as if I dosed daily. Turning off the UV for a short time on a very regular basis like that still reduces effectiveness and increases the frequency of cleaning needed as biofilm grows very quickly on the quartz sleeve (and other microbes in the water). When you turn the UV back on they will be killed stuck to the quartz sleeve, or floating in the water, so personally I now think it's best to use it 24/7 if at all.


Interesting, some stuff I didn't think about. Thanks.


three-fingers said:


> DTPA is still affected by UV, possibly less so than EDTA (but I'm not sure). If your going as far as using fancier chelators this is maybe be a good reason not to use UV.


Well, I just plan to use NilocG Thrive for the first year but, plan to have some DTPA or Ferrous Gluconate on hand for any signs of iron deficiencies. I was hoping to be able to use a UV Filter on this tank but, didn't know about it affecting certain micros.


three-fingers said:


> Hmm, a non-replaceable bulb in 2022 lol. I guess that makes sense for Hagen as they dont make the bulbs so can't sell them directly...our poor planet though.


Well, it has a 2 year repair/replacement warranty so one would be covered for 2 years at least. But yes, I think a replaceable design is better overall. That said, this has some features not found in other models.


three-fingers said:


> Kinda sceptical about the claim about CCFLs being useful 3x as long as traditional UVC  CFLs too, having used CCFLs in DIY lighting over aquariums before.


Yeah, can't say either way there but, again 2 year warranty at least so they must be somewhat confident in the longevity of their product.


three-fingers said:


> It's only 3w, and seems to be marketed to fit into an existing external filter loop - which would mean a high flow rate reducing effectivness. Also it's quite compact, and I've not seen the internal design, but I'm guessing dwell time is quite low.


Well, it is specifically made for the flow rate of the 07 lineup and says it can handle tanks up to 400 Liters. Their literature also mentions this...

Condensed design redirects water flow up, down and around the bulb to maximize contact time for effective clarification




Whether that adequately increases dwell time or not, who knows lol. Could just be fancy marketing but, I have had good luck with most Fluval products. They are usually pretty well designed.


three-fingers said:


> So maybe useful for preventing/clearing greenwater quickly when initially setting up a tank, but a waste of 3w long-term IMO. 3w could be spent on something more useful, like a wavemaker/airpump.


I plan to install an AI Nero 3 in this build as well. I just thought after reading Diana Walstad's paper, that a UV Filter is a good idea too. That was before I knew about the effects on micros. I am building my dream tank here so any advantage is being investigated. I may need to further consider whether the UV is a good addition or not. I'm not concerned with cost, within reason of course, I just really want to build the best setup possible for the highest chance of success(shooting for a world class aquascape here).


three-fingers said:


> Could be very effective on a nano tank with a tiny filter, and more convenient than larger units.


Thanks for all of your help, it has given me some things to think about. Please feel free to add any other suggestions or constructive criticisms you can think of as I am very new to the hobby and on a quest for knowledge👍.


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## FISHnLAB (21 Oct 2022)

_Maq_ said:


> All marketed chelators are _organic_ compounds. As a rule, all organics are more or less subject to degradation when exposed to UV.
> The question is whether you actually need _chelated_ micronutrients.


Please read the post I just posted and add any suggestions or constructive criticisms you have. Thanks for the input👍.


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## KirstyF (22 Oct 2022)

I put a huge UV on my system 2 months ago and I run it 24/7.

Can’t say I’ve noticed it causing issues with my ferts and my micros are leaner than some. (I’m hard water and use chelated) 

How much benefit they are is a tougher call. I am personally only using it for possible fish health benefits and that means it needs to be a fairly strong unit. Lower powered units are not effective for this. 

So, if the micro issue is the only thing holding you back, my personal experience would be that this doesn’t seem to be too big of an issue.


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## erwin123 (22 Oct 2022)

I use an in-tank UV for 4 hours after algae scraping and water change to zap the algae in the water column. 
It has really helped to reduce the amount of GDA on the glass that I have to scrape off each week.


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## MichaelJ (22 Oct 2022)

KirstyF said:


> How much benefit they are is a tougher call. I am personally only using it for possible fish health benefits and that means it needs to be a fairly strong unit. Lower powered units are not effective for this.


That's mostly my take as well. I have had a UV filter in both my tanks for a long time. It never caused me any issues that I am aware off. It's supposedly good for killing some algae spores and some pathogens that floats in the water column. It's very hard to quantify the value of it however. I would definitely consider a UV filter to be in the nice-to-have category.

Cheers,
Michael


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## FISHnLAB (22 Oct 2022)

KirstyF said:


> I put a huge UV on my system 2 months ago and I run it 24/7.
> 
> Can’t say I’ve noticed it causing issues with my ferts and my micros are leaner than some. (I’m hard water and use chelated)
> 
> ...


Good to know, thank you for the information👍.


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## FISHnLAB (22 Oct 2022)

erwin123 said:


> I use an in-tank UV for 4 hours after algae scraping and water change to zap the algae in the water column.
> It has really helped to reduce the amount of GDA on the glass that I have to scrape off each week.


Good to know, thanks👍. Do you leave it in the system of take it out after use? I guess I could always get an I tank one and only throw it in when in use.


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## FISHnLAB (22 Oct 2022)

MichaelJ said:


> That's mostly my take as well. I have had a UV filter in both my tanks for a long time. It never caused me any issues that I am aware off. It's supposedly good for killing some algae spores and some pathogens that floats in the water column. It's very hard to quantify the value of it however. I would definitely consider a UV filter to be in the nice-to-have category.
> 
> Cheers,
> Michael


Thanks for the post👍.


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## MichaelJ (22 Oct 2022)

FISHnLAB said:


> Good to know, thanks👍. Do you leave it in the system of take it out after use? I guess I could always get an I tank one and only throw it in when in use.


If you can find an inconspicuous location for it in the tank (hidden behind some hardscape etc.) , you can just have it on a timer and run it as needed. That can potentially also greatly enhance the lifespan  of the UV bulb which are not cheap. 

Cheers,
Michael


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## erwin123 (23 Oct 2022)

FISHnLAB said:


> Good to know, thanks👍. Do you leave it in the system of take it out after use? I guess I could always get an I tank one and only throw it in when in use.







I take it out after use - the main function is to zap the algae and other stuff floating in the water column after my maintenance/water change.

This is a photo of a 100micron pad installed 1 hour after water change and maintenance. My maintenance technique - scraper/toothbrush leads to algae being dumped into the water column. 
Hanuman's suggestion is to use paper towels to rub off algae instead of scrapers/brushes which dump the algae into the water column, so thats another possible solution.

With 10x filter circulation, the tank water should have gone through my canister filters 10 times after 1 hour. Despite this, there is a green algae in the water column not visible to the eye (and not caught by regular filter sponges).


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## FISHnLAB (24 Oct 2022)

erwin123 said:


> I take it out after use - the main function is to zap the algae and other stuff floating in the water column after my maintenance/water change.
> 
> This is a photo of a 100micron pad installed 1 hour after water change and maintenance. My maintenance technique - scraper/toothbrush leads to algae being dumped into the water column.
> Hanuman's suggestion is to use paper towels to rub off algae instead of scrapers/brushes which dump the algae into the water column, so thats another possible solution.
> ...


Thank you for the added information, it is helpful👍. I kind of like the idea of a removable in tank one like you are using. It offers a lot of benefits. I'm going to have to think this over...


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## FISHnLAB (9 Nov 2022)

Do you guys think the A-A Green Killing Machine 9watt would be a good fit for my new UNS 60U build? I plan to only mount it temporarily in the tank when needed(maintenance day, wildlife and plant introductions, green water outbreaks, etc.). Thanks👍.






						GKM Green Killing Machine | AA Aquarium
					

Turn Green water into Clear water in days with GKM by AA Aquarium




					www.aa-aquarium.com


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## MichaelJ (9 Nov 2022)

FISHnLAB said:


> Do you guys think the A-A Green Killing Machine 9watt would be a good fit for my new UNS 60U build? I plan to only mount it temporarily in the tank when needed(maintenance day, wildlife and plant introductions, green water outbreaks, etc.). Thanks👍.
> 
> 
> 
> ...


I have been using the Green Killing Machine (GKM) 9 watt for years in both my 150 L tanks - see my posts above on this thread.  I clean my GMK's like once a month or so - very easy to maintain.

Cheers,
Michael


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## FISHnLAB (9 Nov 2022)

MichaelJ said:


> I have been using the Green Killing Machine (GKM) 9 watt for years in both my 150 L tanks - see my posts above on this thread.  I clean my GMK's like once a month or so - very easy to maintain.
> 
> Cheers,
> Michael


Ok, I wasn't sure which one you had Michael, perfect thanks👍.

I'm still trying to decide whether I want to spring for an inline one(thinking Coralife 6X Turbo if I go that route) or just keep it cheap and go with this GKM one and just put it in the tank at night when needed. Decisions decisions...


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