Sizing a UV for Reef Tank - Any truth in this ?

[14 foot reef]

Working with my supplier for my new UV and reading some info on there website. There PDF Chart for Sizing a UV for a Reef tank with coral and live rock states this............

Salt Water UV Sizing Chart

Reef Tanks -A UV rated in the 30,000-45,000 columns is ideal for the reef environment .UV’s rated
at higher kill rates will destroy the planktonic food supply for the reef.
Marine Fish Tanks (No reef or live rock). A UV rated in the 75,000 to 90,000 columns will be the most effective at controlling fish disease.
All UV dosages are calculated at end of lamp life (14 months)

So reading this, they are saying that you can't run a UV sized to "kill parasites" as it will kill all Planktonic food. If that's the case then in there eyes you can not run a UV to kill parasites in a reef, you can only run UV to kill algaes, am I missing something here ? Have a majority of you successfully run a UV at 90,000 μw/cm² in there reef, controlled parasites and had a healthy thriving reef.

 

[Brew12]

Working with my supplier for my new UV and reading some info on there website. There PDF Chart for Sizing a UV for a Reef tank with coral and live rock states this............

Salt Water UV Sizing Chart

Reef Tanks -A UV rated in the 30,000-45,000 columns is ideal for the reef environment .UV’s rated
at higher kill rates will destroy the planktonic food supply for the reef.
Marine Fish Tanks (No reef or live rock). A UV rated in the 75,000 to 90,000 columns will be the most effective at controlling fish disease.
All UV dosages are calculated at end of lamp life (14 months)

So reading this, they are saying that you can't run a UV sized to "kill parasites" as it will kill all Planktonic food. If that's the case then in there eyes you can not run a UV to kill parasites in a reef, you can only run UV to kill algaes, am I missing something here ? Have a majority of you successfully run a UV at 90,000 μw/cm² in there reef, controlled parasites and had a healthy thriving reef.

I think you are missing the flow portion. Only a small fraction of the water is going to run through the UV and will constantly be being diluted. You won't be able to kill all of the planktonic food in the system (although corals can still eat the dead stuff just fine) just like you will never kill all of the parasites.

 

[Mortie31]

To kill parasites and bacteria you need to be running very high UV so in effect it becomes a Steriliser, your quite right low power units will do nothing other than kill algae... most Uv’s sold for tanks are not powerful enough to “sterilise”. A lot of people do use them, though I’ve never been convinced of the reason myself, be interesting to see other posts on the subject. I run 2 110W UV’s in my Koi pond which control algae nicely but nothing else.

 

[14 foot reef]

I think you are missing the flow portion. Only a small fraction of the water is going to run through the UV and will constantly be being diluted. You won't be able to kill all of the planktonic food in the system (although corals can still eat the dead stuff just fine) just like you will never kill all of the parasites.

Should have included more info, I run Dual Suntail Reeflo pumps, they each runaround 4000 gph, I will run 1 reeflo at 4000 gph through the UV. The total water volume in the system is 850 gallons so that's about 5 times turn over an hour of total tank volume through the UV...... My issue is they are saying I should NOT size it higher than 45,000μw/cm² flow rate for a Reef Tank. If that's the case, I will not be able to kill any type of ich. And a few things I have read, the Florida Study, and also other companies data concerning ich flow kill rate suggest I should be running a kill rate 2 or 3 times the 90,000 μw/cm².

Thanks for any help on this sizing problem on the new UV.

 

[Mortie31]

Should have included more info, I run Dual Suntail Reeflo pumps, they each runaround 4000 gph, I will run 1 reeflo at 4000 gph through the UV. The total water volume in the system is 850 gallons so that's about 5 times turn over an hour of total tank volume through the UV...... My issue is they are saying I should NOT size it higher than 45,000μw/cm² flow rate for a Reef Tank. If that's the case, I will not be able to kill any type of ich. And a few things I have read, the Florida Study, and also other companies data concerning ich flow kill rate suggest I should be running a kill rate 2 or 3 times the 90,000 μw/cm².

Thanks for any help on this sizing problem on the new UV.

Most UVs are not strong enough to kill ich and parasites, you will need a massive one and with a very long contact one to sterilise, but then it will nuke all of your bacteria as well...

 

[hart24601]

I have wondering this before.


Sterilization rates are listed for single pass, I have often been curious what effects a closed system have on rates, that a single pass could leave the organism alive, but attenuated. That is weakened to the point of being unable to infect or reproduce. With the entire volume of water going back through the UV once per hour (lets say) there is a good chance this organism is going to not recover in time before another pass and be further damaged depending on growth rate. And for our purposes attenuated to the point inability to infect (say parasite) is good enough. These studies do not exist, but they are something to consider.

With most ratings, they are only concerned with single pass as for things like drinking water you only put it though once.

 

[14 foot reef]

I have wondering this before.


Sterilization rates are listed for single pass, I have often been curious what effects a closed system have on rates, that a single pass could leave the organism alive, but attenuated. That is weakened to the point of being unable to infect or reproduce. With the entire volume of water going back through the UV once per hour (lets say) there is a good chance this organism is going to not recover in time before another pass and be further damaged depending on growth rate. And for our purposes attenuated to the point inability to infect (say parasite) is good enough. These studies do not exist, but they are something to consider.

With most ratings, they are only concerned with single pass as for things like drinking water you only put it though once.

This is a great thought on this, if this is possibly true, then at my 5 times an our turn over, I might be able to get away with a little bit smaller unit.

 

[Mortie31]

A question on the subject, if there is no proof that the UVs rated for our tanks actually kill ich, and without a negative effect on bacteria etc why do people put them on there tanks?

 

[evoreefer1320]

A question on the subject, if there is no proof that the UVs rated for our tanks actually kill ich, and without a negative effect on bacteria etc why do people put them on there tanks?

I have one on my tank to battle dino's. It is the one thing that seemed to work to keep them in check.

 

[hart24601]

This is a great thought on this, if this is possibly true, then at my 5 times an our turn over, I might be able to get away with a little bit smaller unit.

We just don't know, it sure doesn't hurt to shoot for single pass, but very well might not be needed. I have noticed over the years that many report good results with UV treating issues, I don't mean ich - more like dino or green water, with sizing below what should work and that got me thinking about it.

Is oversized singlepass sterilization better but with a very low flow of 1x turnover per hour, or undersized with 10x turnover work better? For organisms that reproduce slowly (in microbiology time or parasites) high turnover might work very well depending on the ability to fix the DNA damage. Also how likely is it the organism will even find it's way into the uv? The aquarium flow rate might come into play as well there along with things like bare bottom.

Just a lot to consider.

 

[hart24601]

A question on the subject, if there is no proof that the UVs rated for our tanks actually kill ich, and without a negative effect on bacteria etc why do people put them on there tanks?

Most of the bacteria we "like" are attached to substrate in biofilms. UV will not touch them because they are not in the water column.

Many secondary bacterial infections are caused by a weakened immune system which should be addressed before the bacteria, however it's possible UV reduces the amount of opportunistic bacteria in the water column which could help prevent these infections in compromised animals.

 

[Mortie31]

I have one on my tank to battle dino's. It is the one thing that seemed to work to keep them in check.

Are dinos water born? And hence would they get into the UV? As surely anything that is on the substrate or rock work wouldn’t get near the UV, I’m not being funny I’m genuinely interested, we know they re fantastic at killing water born algae

 

[evoreefer1320]

Are dinos water born? And hence would they get into the UV? As surely anything that is on the substrate or rock work wouldn’t get near the UV, I’m not being funny I’m genuinely interested, we know they re fantastic at killing water born algae

Well some but not all dino's cling to the rock or sand during the day and at night go into the water to feed. UV tends to work on some dino's but some have a thicker shell that the uv doesn't work well on. Lucky for me it's working on the type that i have.

 

[Mortie31]

Well some but not all dino's cling to the rock or sand during the day and at night go into the water to feed. UV tends to work on some dino's but some have a thicker shell that the uv doesn't work well on. Lucky for me it's working on the type that i have.

Cool thank you...

 

[brandon429]

Planktonic feed doesn't matter. Once free of that limitation in the claim, what's the next holdup you see preventing you from buying the largest oversized one you can afford and install, doesn't have to run all the time if not wanted

The best option you could employ for uv is most gallons beyond your own rating, still installed well. The ways we kill, bind, impeller and sock trap planktors in non uv setups renders the limitation neutral as written above

If they mattered, we wouldn't need supplementary feeding. They're ideals, like a pH of 8.2, incidentals.

Every pico reefer I know packed with sps is changing all the water, talk about insult

 

[Steve Fast]

I went through the same exercise about 6 weeks ago. Seems like we've both found the same U Florida extension article (http://edis.ifas.ufl.edu/fa164) which gives an industry standard of 280,000 µWsec/cm2. So I set my flow to dose UV at 360,000 µWsec/cm2. Then I purchased sufficient UV power ( in my case 2 units at 150 watts each) to turn 99.9% of the tank over in 4 hours according to Hamza's calculator (https://www.hamzasreef.com/Contents/Calculators/PumpTurnover.php). This means that, assuming uniform distribution of the pathogen (reasonable enough given the internal flow in the tank), the buggers have much less than 4 hours to find a host. This knocked the ich out in my tank after the existing parasites had fallen off their hosts in ~ 4 days. No signs since then which has been over 4 weeks... Was very rewarding to see the fish liven up and swarm for food once again...

Hope this helps....

 

[ca1ore]

Right, a few misconceptions in this thread:

1. While a UV set to 'sterilize' will indeed kill planktonic animals, there are essentially none in a reef tank anyhow, so it's irrelevant.
2. Bacteria that pass through the UV will be killed, however as noted, the bacteria we care about are living on the substrates so it's also irrelevant.
3. UV will not eradicate ich because it mostly hides in the sand and there's almost no chance that the free swimming stage will all go through the UV before encountering a fish.

Whether a UV sized to sterilize reduces parasite pressure in a reef tank is speculative. It seems like a reasonable assumption to me, but absent actually testing for numbers it remains unproven.

 

[Steve Fast]

The U Fla article cites that the theronts are released at night when fish are least active and near the substrate because, it is suggested, to better find hosts. If the water flow is high and the theronts unable to direct their movement in the current, upon their release from the tomont, they will be mixed uniformly in the tank. Unless the theronts can swim counter to current, mixing will occur which would mean that some of them would be eradicated by the UV. That said, I have not found any information on the mobility of the theronts in current. Further, fish might sleep where the current is not as strong which could improve the theronts' success rate.

 

[brandon429]

Garlic has been given equal claims like the above for ich control

Uv doesn’t work for preventing ich/carion. Can’t hurt as backup, but in the ich threads crypto threads here where stat significance is shown, uv isn’t part of the new trending ways of tank transfer protocols, quarantine, and fallow setups


Try to locate threads where the actual ich cures or preventions were logged into one place and link here for compare and contrast, show uv actually accomplishing it in say eight tanks all in one thread





If you bought the best uv array you could get, and skipped fallow Ttm, then added a bunch of new tangs, you’d have crypto regardless of the uv. if I owned a large tank it would have uv, but not using the info above

Doesn’t hurt one bit to try and see what happens, but having to redo fallow five years from now/not fun

If a college or researcher wrote a paper advising uv to cure or prevent marine crypto, don’t buy in fully till you see their work in more than one home aquarium in a thread is my reco. They have a lot to prove to undo the current techniques which are used due to consistency in results. some of the uv published info is decades old now, it’s really hard to find new ways to use UV in reefing/been deeply investigated. The sole reason fallow/ttm/qt exists is due to shortcomings of uv helping in the matter.

Research threads and google scholar links on uv and application options: myriad

Actual live threads where uv cured crypto and we can track long term results clearly in one place: awaiting links.

If someone wanted to see stat significant curing and prevention of crypto—> fish forum/humblefish what is he up to 95% consistency now I forget, way past statistical significance

Quarantine ttm and fallow does have the threads we need for proof, can’t wait to see a uv one, not a uv/pro con thread, an ich curing one

 

[Steve Fast]

First a bit of background… I have a big system and when an outbreak occurred, the choices were few. One choice is to allow everything to perish and let the system go fallow, something I was disinclined to do as it would cost my fish their lives. Other treatment options were equally unpalatable. So I investigated UV and below details what I found and thoughts for better methods to determine UV’s efficacy. My initial results are found above.

As the U Fla summary article and other sources state and for reasons also previously stated, UV is not a recommended choice for eradicating ich. The U Fla article does however give industry standards for recommended power levels to kill the parasite (good to know that industry uses UV which is some, though not a complete, indication of its efficacy). Also, as is well stated above and other places, there have not been any experiments to decide this question. The experimental design would have to account for all the factors, which might it extensive and hard to execute. In the absence of a controlled experiment, I chose to use a simple mathematical model. Mathematical models and computer simulations are used regularly to answer questions where experiments are not feasible. My model was very simple and only accounted for kill rate (100%), tank volume, and flow rate through the UV. This is certainly a limited model, though for a back of the envelop calculation, easily enough to do. Specifically, the model does not account for fish density, a serious limitation. Fish density could be added by making some simple assumptions using surface area of the fish population, water flow, etc. This model would be an extension to the model I used which used the computations found on Hamza’s site stated above and the citation he references (Aquatic Systems Engineering: Devices and how They Function, by Pedro Ramon Escobal). It is basically a first order differential equation, which could be extended to account for fish surface area and, once defined, not difficult to solve. At some point I may solve it. Another option is to use a more complex model. Agent-based computer models/simulations have been used in epidemiology studies and many factors could be included such as: mobility of parasite, water flow, fish density and movement, parasite density, UV kill rate, etc. It would be an interesting and fun project and could not only answer questions about UV, it could also be used to evaluate other treatments. That said, building the model would require more work and commensurate compensation for the development team. If anyone is interested in pursuing this, let me know and we can identify a funding source and write a proposal.