Opinions on UV?

Discussion in 'Equipment' started by rygh, May 3, 2018.

  1. rygh

    rygh BOD

    As part of my tank-reboot, I have been considering adding UV.
    I know it is not magic for a reef tank, but it can help.

    Primary reasons:

    1) Keep the water clear.
    I ran UV on fresh water long ago, and it was amazing for clearing up the water.
    Carbon can do similar of course.

    2) Reduce film algae
    It kills free-floating algae, slowing spread to front glass, etc.
    So in theory, reduces maintenance.

    3) Reduce bacterial problems.
    Less likelihood of Dinos and Cyano.
    Which is an issue since I carbon dose.

    I don't really consider UV effective against ich or other parasites. But debatable.
    Not cheap, since I need a decent sized one.
    Will kill a few beneficial pods, bacteria, and so on. But so do skimmers and pumps.
    Power use is really not an issue, since almost all energy ends up heating water, reducing heater use.

    Other opinions??
    Good/Bad/Waste of money.

    Anyone have a good used one in the 50-80W range?
    Mozby likes this.
  2. euod

    euod Supporting Member

    I can confirm UV keeps water clear and effect against ich.
  3. sfsuphysics

    sfsuphysics Supporting Member

    One of the keys with UV is flow rate, too fast and you give stuff passing through nothing more than a suntan.

    I would probably rate it in the same category as ozone usage, can absolute have its place but not a necessity type of item like a protein skimmer
  4. Funny you asked this today -- this just arrived 30 minutes ago:
    rygh likes this.
  5. Flagg37

    Flagg37 Supporting Member

    I had always considered uv as practically useless but BRS just recently found that the only tank that has uv on it has significantly less algae (their ulm series). They haven’t conclusively said it’s from the uv but it’s a possibility at this point. They did echo what @sfsuphysics said about flow rate. They’ve got a Neptune flow monitor on it to make sure there’s a proper amount and not just guessing.
  6. rygh

    rygh BOD

    So flow rate is a bit of a debate.
    Obviously too fast is totally pointless.

    But there are really two flow targets: Algae speed, and Parasite speed.

    Algae Speed:
    Roughly 20 GPH/Watt
    Kills algae and small bacteria.
    Parasite speed:
    Roughly 5 GPH/Watt
    Kills relatively large parasites, plus algae and bacteria.

    The downside to the low flow is that it does not turn over your tank water as often.
    Which means it is WORSE for killing algae and small bacteria because the odds of them going through drop.

    For me, I am not looking for UV to kill ich, so may tend toward the faster one.
  7. But it's not that simple actually is it? It really boils down to exposure time so flow rate alone doesn't cover it. For instance, if your UV source is eight inches long you would need a very slow rate indeed, but if the exposure is from a three foot bulb the GPH can be faster for a still better result. The other thing not factored in here as far as for parasites is you don't have to aim for 100% eradication to make a difference. If you can disrupt 50% of the population you will still have smaller and less frequent outbreaks that should be more survivable.
  8. euod

    euod Supporting Member

  9. NelsonCh

    NelsonCh Supporting Member

    I have either a 40W or 60W UV I previously used for 3 months. If you are looking to buy one, pm me.

    Not sure if pond UV experience is the same but look at before UV installed and after UV installed.



    3 days. With 4000gph pump through a 60W.
    From my experience, your flow has to be insanely fast for any algae or pests to survive. This was outdoor where excess nutrients/light was uncontrollable. Still did wonders.

    Sent from my iPhone using Tapatalk
    Last edited: May 4, 2018
    rygh likes this.
  10. Adit0

    Adit0 Guest

    I can attest to UV being helpful but not magical. I saw a very noticeable decline in dinoflagellates when i added a UV, but they didnt go away until I did some other things as well. I also haven't seen ich on any of my fish since I added it in, even after adding in new fish(with quarantine but the stress created should have caused ich if there was any in the system). I'm pretty sure I had ich before, but I havent seen it in a year.
  11. Kmooresf

    Kmooresf Supporting Member

    I’ll let you know. Dealing with a large ich outbreak and put a high output 50w unit in at 250 gph. Water looks amazing. Time will tell if it helps the ich. Attempting to dip all fish in freshwater followed by a medicated bath, but a couple fish just won’t be caught. We’ll see.
    rygh likes this.
  12. Flagg37

    Flagg37 Supporting Member

    Uh oh. What did you add that had it?
  13. Kmooresf

    Kmooresf Supporting Member

    Been having trouble adding fish, due to a very aggressive and mean six line wrasse. Smallest fish in the tank, and a total A-hole. We decided to add multiple fish at once to try and lesson the aggression. Worked very well. We added a small female star leopard wrasse, a long nose butterfly and the biggest tile fish I have ever seen in my life. All were very fun pics, and all of them acclimated very quickly and with very little aggression. We were so stoked!! For about a week, when we started noticing the tangs getting ich. The butterfly had a little after that week, but mostly the tangs.

    We lost the butterfly and the tile fish first. Followed by my GIANT and insanely beautiful male spotbreast angelfish. None of them would be caught. I have managed to catch and dip almost all of the other fish, but my mimic tang will NOT be caught. It is painful to watch as he is very uncomfortable.

    The dipped fish are not out of the woods either. Purple tang is still having issues and the powder blue, but they are both WAY better than the mimic, who is miserable. Have had the mimic for about 5 years. If I remember correctly, it was one of the first fish we added to the 300 once it was set up. It’s possible he was in my old 120 Fowler before moving to the 300.

    Anyway, it’s really bad. Set up a freshwater bath each night, and a small tank with some iodine based medication for a bath that follows the dip. Then I stand on a stool and wait. Seem to catch about 1 or 2 fish an hour. 4min dip and 30min bath. It’s been such a pain.

    On a good note, the corals and inverts look fantastic. The water is stunningly clear with the UV.

    Sent from my iPad using Tapatalk
  14. NelsonCh

    NelsonCh Supporting Member

    Very sorry to hear this... Even with such great effort and precautions, fish still die and contract diseases.

    Atleast you tried your best and wont live with regret thinking, “Maybe if I tried this, none would have died.” At the end of the day, what matters most is you cared and tried. It just didnt work out.

    Do you get your fish online, from a hobbyist, or LFS?

    Sent from my iPhone using Tapatalk
  15. Just a thought on your treatment protocol. While Tangs are more susceptible to Ich issues than some other species, it can be managed in most cases in tank and the most important part of managing it is to create a stress free environment where the fish are well fed. You may be causing more harm by netting and treating them nightly. I believe your bettr off leaving them in-tank, feeding heavily especially with Nori. The alternative would be to net them just a single time and then run them through a TTM protocol where stress is a little more minimized.
  16. Kmooresf

    Kmooresf Supporting Member

    Thank you. I have had a few of these fish for over 10 years, with my oldest turning 16 soon. I am pretty bummed out about it.

    It was a LFS, but I’m not gonna say which one. I know very well, that no matter how reputable a place is, there is always a risk of disease. I choose not to keep a separate / proper quarantine system at home, so I know it’s a risk. We all take that risk buying from anywhere.

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  17. Kmooresf

    Kmooresf Supporting Member

    I actually agree Bruce, and thank you for the input. I am actually not catching them daily. Just the ones that I haven’t yet caught. My Mimic is the real target, as I am not sure he will live if I can’t get him dipped. I have upped the feeding, and am feeding Nori on the regular. They are all very active and feeding very well. The powder blue and purple are much more relaxed and seem to have done well with the dips. Mimic is quite stressed and rubbing on pretty much everything.

    I have seen some pretty interesting behavior with this event. I have two blood shrimp, and they have become quite the cleaners. The mimic is in their cave sometimes 5 minutes at a time, and they are on each side of the tang, cleaning away. I have also witnessed my school of chromis cleaning the tang. I had no idea that could happen. The mimic holds really still with chromis on all sides, taking turns. Pretty amazing really. He had ich all over his eyes before, and doesn’t seem to have it anymore. Just not sure that is enough.

    Mike (fishdoctor) came by and has been helping me with the treatment plan. Also did a big water change in addition to adding the UV. Haven’t pulled the trigger yet, but researching medicating the food as well.

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  18. scuzy

    scuzy Supporting Member

    I've been ich free for 2.5 -3 years been very careful but recently added a Walt Disney colony and ich came with it. Now I just let them be and try not to stir up the tank. Seams to be working.

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  19. Mozby

    Mozby Supporting Member

    Would it be a good thing to add a UV sterilizer to a 20g tank when there are no glaring issues? In terms of flow, GPH in return pump is 230 and there’s an mp10. Would a uv sterilizer slow the flow down?

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  20. rygh

    rygh BOD

    There is little friction, so flow should not be "caused" by the UV.
    However, depending on the size of the UV, you may decide to slow flow down, to increase effectiveness.
    Note that UV does add heat, which could matter in a small tank.

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