Impact of UV on algae ?

[kevensquint]

Hello I was wondering having never implemented a UV sterilizer what kind of impact it has on keeping algae at bay. I want to slightly increase nutrients in a system that reads 1ppm NO3/0.00ppm PO4. To say 2ppm NO3/ 0.02 PO4. ATM film algae appears per 2 days on the glass. Which is still fairly quick, I'm assuming by increasing nutrients I might even provoke some GHA. So, from experience is a UV worth it in this case?

 

[clsanchez77]

I run a UV on my system from day 1 based on recommendations from others, so I don't have a w/o to compare too. UV will not kill attached algae growth, it will only "sterilize" (not kill) free swimming cells. This is why they are referred to as "clarifiers" in the pond industry.

So in theory they do help with the micro nuisance algae. But they do nothing for nutrients, so if you are killing the micro algae through UV sterilization, then the nutrients will just favor the macro algae instead.

Does that help?

FWIW, they will also prevent any bacterial blooms and if set properly can help 'mitigate' (not prevent) free swimming stages of various fish parasites. Proper flow rates are key.

 

[brandon429]

amazing summary of UV there, agreed. if they made thumb sized ones, id use them in pico reefs. Best reefing cheat I know of besides skimmers

indeed they are pelagic interceptors. Much of the reason we see algae challenge threads as cyclic/growback/repeating cleaning hassles is because the act of cleaning a tank of algae is fragmenting, helps it reproduce and seat in elsewhere though a major mass was removed.

UV helps right then, after cleaning, catching circulators

and then if you just start a tank with one, preventative right off the bat. What living things they may zap in the water don't mind, we have functioning food webs in tanks that constantly replenishes things + retail additives too to make up. I would never ever run a full sized tank without one. Not that they're required, but the headaches they remedy beats Tylenol. go big or go home too

Id never run the correct UV sterilizer for my gallonage. I would only run a pond sterilizer that was so large it would have been hard to work with. Correctly sized ones work, but gross oversizing burns even better

 

[brandon429]

if I had to select the number one tank invader UV will help cheat out its cyano and spirulina and diatom invasions.

UV made a huge impact on my filamentous hair algae problems only because I was cleaning as the primary mode of control. arresting those floaters/zapping them to prevent growback allowed my cleaning to overtake the plant mass, I consider UV helpful across the board for algae but the cyano bacteria especially. people will chase nutrients, clean sandbeds, rip clean tanks to get rid of cyano and usually any form of UV filtration after a thorough tank cleaning prevents it from coming back. very helpful for moneran invader mats.

 

[kevensquint]

Ok Well my goal is to slightly raise nutrients and not cause a significant increase in algae. Nothing to do with the algae already on the glass or rocks. That said I just ordered a 40w unit for my 160. Not a Chinese one either...pretty expensive:I

 

[kevensquint]

Thanks for the input

 

[kevensquint]

Actually I wonder what impact if any a large UV might have on the annoying "vibrio sanjay Joshi acro meltdown" deal. That can occur with warmer weather ( temps)

 

[clsanchez77]

if I had to select the number one tank invader UV will help cheat out its cyano and spirulina and diatom invasions.

UV made a huge impact on my filamentous hair algae problems only because I was cleaning as the primary mode of control. arresting those floaters/zapping them to prevent growback allowed my cleaning to overtake the plant mass, I consider UV helpful across the board for algae but the cyano bacteria especially. people will chase nutrients, clean sandbeds, rip clean tanks to get rid of cyano and usually any form of UV filtration after a thorough tank cleaning prevents it from coming back. very helpful for moneran invader mats.

I managed to get a pretty big cyanno outbreak while on vacation recently. When returned, I caught up on all my tank maintenance. Upon disassembling of my UV, my procrastination was very evident. Took me 2 hours to get the build up off the quartz sleeve. Do keep those quartz sleeves clean!

I personally do not think the size of the UV is all that important. Most of our reef tanks are very small relative to ponds. What is very important is the flowrate through the UV. Follow the manufacturer's recommendations for your goals. I prefer AquaUV as they have been around a very long time.

Regarding the tank food chain, I don't buy it. My tank has a very healthy pod population and I only add pods to the refugium...so they are making it through and still breeding. I don't dose live phyto, ciliates or rotifers so I can only speculate. Seems amphipods survive the trip through the unit.

FWIW, I only run an AquaUV Classic 15W unit on a 110 gallon reef and I run 110 gph through the unit in parallel to my main tank return (1x tank turnover). I am estimating about 25% of my return flow through the UV. I hope to install the Apex FMM kit one day to truly dial it in and understand my flows better. My estimated radiation is 180,000 µw/cm2, which will reportedly sterilize everything up to protozoas. I have not noted any ill effects.

 

[brandon429]

nano reefers tend to do mostly or all volume water changes which also sets the water pretty clean...I never concerned much over food chains, rods feed is my food chain lol