Running a 36 watt UV sterilizer on my 60 gallon

[Andrew H]

Wanted to share an update on my experiment in extreme UV. I was struggling with a high degree of unexplained fish mortality in my 60 gallon. I’d lost a pair of cacatuoides, and then a pair of borellii, each over the course of 6-12 months. The Borellii had spawned and all but one of the fry disappeared over weeks (they were isolated with a tank divider, fed with BBS). Nothing out of the ordinary for water conditions, weekly 40% water changes.

I had started to suspect my tank had mycobacterium, and after trying a few of the tiny UV sterilizers (eg the fluval 3 watt unit) without success, I got desperate and went asymmetric - in May of 2024 I installed a stainless steel 36 watt UV sterilizer (Jebao brand, $125 on Amazon, made for ponds up to 8,000 gallons!!!). The plumbing required was a little bit of a trick but it sits inline after my canister filter. This level of UV is easily lethal to any microbe, algae and even multicellular parasites. I run it 24/7 and it raises my water temp by a couple of degrees (so I adjusted my heaters down). After 6 months without issues, I scaled back water changes to 25% once ever 3-4 weeks (it’s a heavily planted and understocked tank). It’s been 12 months and I’ve had zero death or illness. This isn’t exactly a scientific experiment but this is easily the most beautiful, easiest to maintain and stable tank I’ve ever had. I suspect that a sterile water column, while it may sound unnatural, is closer in bacterial load to natural habitats than an aquarium is, and prevents opportunistic infections.

Picture is of my sole surviving borellii from the spawn, “big baby” (my 8 year old gets all the naming rights).

 

[MacZ]

I'm sceptical of the UV sterilizer really being the reason everything is running smoothly. I see no causation in the correlation, if you will.

For one: It is widely known that domestic Apistogramma have no high life expectancy and especially domestic A. cacatuoides breeds tend to drop dead quite easy, just as domestic M. ramirezi. 6-12 months after purchase is the average.
Many of these fish fall victim to what I have started calling the Dwarf cichlid sudden death syndrome, which shows basically the same symptoms across species and genus lines. (Loss of appetite, reclusiveness, loss of buoyancy, heavy breathing, then quick bout of dropsy/popeye and finally death, all within 1-2 weeks no matter what treatment you try.) It is suspected this might be how a collapse of the immunesystem due to systemic stress looks like. Due to its sudden onset and lack of early warning signs it is almost impossible to do proper research on that phenomenon, but we have cases around the world.

Secondly and this really makes me wonder: Did you have losses of any other species besides the cichlids? Because that is the really important hint to tell whether it's something obligatorily pathogenic as Mycobacterium.

Did you try and filled out the disease template in our cichlid health subforum?

UV sterilizers have proven to work for a number of parasitosises like Ichthyo (if combined with salt/high temp) and Dermocystidium. They also have helped with making obligatory blackwater species (not the case here) work in tap water. Running a UV for lobgwr periods has shown to make fish prone to more severe cases of bacterial infection if they do come up nonetheless. The pathogen count in the water column is indeed reduced, but the numbers on surfaces should have stayed unchanged.

 

[Mike Wise]

If UV works for you, then keep it going. I personally will continue using my old tried and true quarantine method - at least 6 weeks no matter how they appear and from whom ever they come. A lot less expensive.

 

[Andrew H]

Replying with an image as the spam filter is really aggressive (won't let me post!!)

 

[Andrew H]

If UV works for you, then keep it going. I personally will continue using my old tried and true quarantine method - at least 6 weeks no matter how they appear and from whom ever they come. A lot less expensive.

Dammit - still getting blocked from posting! Another picture (worth 1,000 words)

 

[MacZ]

Ah, one of these antibiotics overusers... Honestly, the symptoms don't sound like Mycobacterium, the species are probe to bacterial infections anyway... It could be an opportunistic bacterium.

I don't doubt the effectiveness of the UV. My point is: Just as with antibiotics the immunesystems of the fish don't have to work much anymore. So you make your system dependend of the UV, probably crashing it once you take it off. Imagine being in a sterile environment for longer periods of time. No pathogens, whatsoever. What do you think will a simple, omnipresent pathogen like... a common cold, do to your system?

If you want to stick to it being Mycobacterium, allright, I would doublecheck by getting a lab test on a sample from your tank.

 

[Andrew H]

Could be true (dependency on UV) but who knows. What is definitely true is that the only way to actually ID fish TB is an autopsy with culture based test, i.e. totally impractical. PCR testing of environmental samples is too sensitive, i.e. you get a lot of false positives as these bugs are found everywhere at low levels.

 

[MacZ]

What is definitely true is that the only way to actually ID fish TB is an autopsy with culture based test, i.e. totally impractical. PCR testing of environmental samples is too sensitive, i.e. you get a lot of false positives as these bugs are found everywhere at low levels.

Doesn't contradict my statement. It will take a lab to confirm Mycobacterium, no matter what the sample is.

 

[martin_c]

To me UVC were never a long term option because they destroy iron chelators and i usually rely on (emersed) plants for nitrate lowering.

@Andrew i'm surprised that your plants are doing good, and wonder if you do daily iron fertilizing?

 

[Andrew H]

I had wondered / worried about that. My plants seem fine, a year in, and I add fertilizer every couple of weeks (very lean). That said, I’m not growing anything too fancy - just a lot of anubias and a few buce and some rotala.

 

[Mike Wise]

Dammit - still getting blocked from posting! Another picture (worth 1,000 words)
View attachment 16813

Just a curiosity question. How often is the UV tube recommended before it is needed to be changed and what does a new tube cost?

 

[Andrew H]

Just a curiosity question. How often is the UV tube recommended before it is needed to be changed and what does a new tube cost?

I’ve heard that after a year it’s a good idea to replace as the uv will drop. That said - 36 watts is so overkill that I might give it a while longer. It’s $22 for 2 replacement tubes though, so not too bad.

 

[Mike Wise]

I don't think that the tube will last longer just because it is over-size for your tank. It still is emitting at full strength. Still $22 is not a lot if it provides peace of mind.

 

[Andrew H]

Definitely - I meant that even if the amount of uv emitted dropped by 50% after a year, it would still be a lot for a tank that size. I hadn’t checked pricing for replacement bulbs but was pleased how cheap they are.