uv sterilization

[sparkey65]

hi there fellow reefers i would like to no some of the pros and cons of using uv sterilization on a reef tank

[rsman]

ok pros
stimulates the economy (while your at it get an eco-analizer thingamiger)

cons
not entirely effective at doning anything good
kills some good micro-organisms
adds heat
something else to maintain
something else to break

[sparkey65]

lol ok thanks

[staticfishmonger]

hey it draws power too and takes up space. also you have to replace the bulb every 6 months or so, well thats stimulates the economy too so maybe thats a semi-good thing. accually for a pond they work wonders, but as far as its use on the reef it is questionable. i had one running on my FO after an ich out break. i also started feeding garlic soaked food. i never had ich again but as for the contribution of the uv i dont really know. to me it seem that if you have excellent water conditions it can make it perfect. but if you only have good water quality it seems to to less if anything at all. i dont know if that makes any sense at all but that was my experience with them.
i have a 25w laying aroud not being used and i have thought about hooking it up to see if there are any improvements.

[rsman]

ooh yea, forgot about space and bulb replacement so your initial purchase stimulates the economy and the replacement bulbs do to :D

sounds like everyone needs to go out and buy one!!! buy two there cheaper than a car :D

well they do have there place a reef is just not one of them. I also took the "fellow reefers" to imply he wasnt using it on his pond.

[staticfishmonger]

yeah but if he was it would be a good addition. our 9,000 gallon pond always had a greenish tint. we then installed a giant uv system and it is crystal clear now. then in about 6-8 months the algae green comes back. so, for that application it is great. i would highly recomend it.

[rsman]

wow 9000g ive only got a 175 :D just a thimble compared to 9000.

[staticfishmonger]

yeah the pond is fun we have it stocked with blue gills, bass and catfish. all locally caught. the blugill have spawned 4 times and many of the young made it and are growing up nicely. one of the catfish is around 15lbs he is a monster. i have gotten in there with a mask and swam around before its a real hoot.

[puzzlenow]

We have tangs in our tank, which are ICH magnets. So after a couple of years of treating ich, I broke down and bought a UV sterlizer. YIPPEE, I am so glad we did. The water seems to be a little bit clearer (maybe) but we have not had an outbreak since we bought the UV. Its been installed for over 2yrs now.

So I like it. !!!

[da colts]

i work at a all marine aquarium shop and have for about 17 years, i use to not believe in themand i would tell my customers that i never used them ......well to make a long story......even longer, 2 years ago i commited the cardinal sin of putting a new fish in my reef 2 days before i went on a weeks vacation. i recieved a call from my daughter about 3 days into my vacation, she was telling me that my new fish(which was a 7 inch clown tang, i know.....kill me)had a pretty bad case of ich.i worried the rest of my vacation, when i returned home every fish in the tank had ich except the six lined wrasse, some were so bad that they were laying on the bottom of the tank(yellow tang, clarkii clown,sailfin tang) i just knew they were all gonna die, i have been doing this hobby for 17 years and i knew how serious this was. i figured i had nothing to lose. i went to my shop and brought home a bottle of rally,and a 36 watt double helix uv(at that time helix's were all the rage and they seemed to be good uv's...live and learn) within a week every fish in the tank except the clown tang who had died right before i returned home, were just about clear and cured....i still have those same fish in my tank today. not sure if it was the rally or the uv or both but i went from a non believer to a believer. so now i do recommend them to all of my customers, i just let them know that flow rate is very important.

[SAT]

The use of UV to prevent or cure Ich (Cryptocaryon) and other diseases is controversial. There is one case where its utility is proven: in an LFS or other large facility it can be very effective at preventing diseases from transmitting between tanks. In a home aquarium it's more complicated. There are published studes that have actually proven, through mathematical analysis and experimentation, that it is impossible to use UV to cure Ich in a closed system. The only reason it's worth looking at is those studies assumed only a relatively low flow rate would be practical and they ignored the effect of the fishes immune system.

First off, UV only kills parasites that go through it. So, the parasites need to be sucked into the UV unit before they encounter a fish. Second, you need enough exposure to either kill or sterilize the parasites or it doesn't do any good.

Our resident pathobiologist, Bomber, has recommended a flow rate of 5X hourly turnover as appropriate for this application. In other words, with a 100G tank, you want 500G/hour flow through the UV unit. Assuming the flow is reasonably even (i.e., no dead spots in the aquarium), that should be sufficient to reduce the parasite population enough so that it's not lethal to the fish (you can then rely on the fishes immune system to finish the job).

As for exposure, the recommendation for Ich is 90,000 uws (micro-Watt-seconds/square centimeter). Note that the exposure required to kill an organism is proportional to the organism's size. Compared to a bacterium, Cryptocaryon is huge. Units sold for pond or hobby use are sized by the manufacturer for killing bacteria and algal spores, not protozoans.

Typical hobby UV systems are sized at about 15,000 to 30,000 uws at 1X turnover. To get 90,000uws at 5X turnover, you need a unit about 15-30X bigger. The last time I went through the exercise, that came out to between 0.5 and 1.0 Watts per gallon of tank water, depending on the efficiency of the unit. Yup, it's expensive. :D

[PaintGuru]

Some lite reading:


http://archive.reefcentral.com/forums/showthread.php?s=&threadid=129757&highlight=UV+sterilizer

http://archive.reefcentral.com/forums/showthread.php?s=&threadid=144760&highlight=UV+sterilizer

http://archive.reefcentral.com/forums/showthread.php?s=&threadid=200188&highlight=UV+sterilizer

[Snailspace]

A fellow reefer has a 550g and recommended UV for my 150g. Waiting for bulb replacement, his powder blue tang showed outbreak of Ich that went away when bulb arrived. So I did one.

Within 2 days my water was clear. Before it had a slight green tint (not from glass). My powder blue was never loaded up with spots but he is spotless almost all the time now. I don't think ich ever really goes away...it is an internal parasite.

What I think is important is HOW you use a UV. I have mine inline to my fuge, not inline to tank return. That means that the flow is slow and less gph. With an est. 1100gph return flow to tank, only about 60gph goes to fuge. Why is that important? I only have an 8w UV...well under the rated size for a 150g + 60g sump. I figured the low flow meant more contact time of water next to UV bulb. Thought perhaps I could get away with a smaller bulb and housing because my kill rate is higher with a lower flow. It also kills BEFORE my fuge. Since a UV kills good and bad bacteria, I feel it is a good setup. I haven't lost much of anything fish or coral and all looks healthy and growing. And who sez you have to run it all the time anyway? If I knew how to post, I could send a pic. Just my 2 cents.

[staticfishmonger]

with the lower watt unit you have it may not be as much of an issue as someone with a larger unit, but remember these bulbs put out some heat and they are in a confined space. there sole source of cooling comes from the water. if the flow is too slow you could end up having a temp problem. that is why there is a big warning label on mine that says never have the bulb on if there is not water moving through the unit at the recomended rate. and as i said with an 8watt unit it probably is not an issue. maybe somthing to keep in mind for people using larger units and trying to set the flow rate.

[Snailspace]

Yes. Temp is a factor. My water temp (approx 78F) is read near UV in sump. As far as the bulb temp, there are precautions when using any UV. Mine, Aqua brand, sez not to run the unit dry for more than 30 minutes. They also caution turning it on/off frequently as it could shorten bulb life. I would add that the mounting is important too. I have mine mounted so inlet/outlet (both on same SIDE of housing) points up. This way, the housing is always filled with water even when flow is off. When I shut my main pump off for feeding, some air gets into UV line by backflow. After turning the pump back on, I open the gate valve to the UV line 1 full turn more than usual for 20sec to flush air out. I only turn UV off if I'm intending to work longer on tank. Having to machine good PVC clips to hold housing as Aqua's do not fit this model properly.

An important note about my arrangement is that I don't feel "big units" are so necessary. I think one should rethink their installation rather than solely going just by a manufacturer's recommendation. Basically, my points are...

1. lower flow = smaller UV
2. smaller UV = less space and cost to purchase and operate
3. regulated UV kill rate (gate valve) = less good bacteria kill
4. UV, IMHO, seem to work for clearer water and cleaner fish.

[staticfishmonger]

yeah when i had a FO i ran a 25w on my 125g and i never had an outbreak or ich, i also always feed with garlic and vitamin supplementation and i strived to keep excellent water quality. also i have run a 120-150watt unit on out 9,000g outdoor pond and it has almost worked wonders, not so much disease control, but for the algae. the water will be green and then with the addition of the uv it is crystal clear, after about 8 months or so the green returns, so i change the bulb. and sure enough it is crystal clear. with the aquarium it is a little harder to see the results and as for how much the UV contributed im not sure, but one of good friends in the hobby also fed with the same supplements i did and he was always fighting off ich and treating with copper. we both bought all our fish at the same store and many times together, two from the same tank. that kinda leads me to think that it did do somthing usefull.
i have yet to add it to my reef as i keep reading mixed reviews, i have a few tangs now so maybe it wouldnt be the worst thing to run. placement of the unit is no doubt an important thing, with mine i think just in the sump would be the only place i could house it. i would hate to cause problems to arrise from adding a piece of equipment that is not a nessecity.. what to do? what to do, im so lost, i cant make up mind.....ahhhhhhhh

[Snailspace]

As this is my third tank, I knew I should listen alot and ask questions, but the tank is mine and no one else is going to maintain it. So ultimately I must take responsibility and think for myself. Everything is a compromise. I have the UV but it is small. That meant I had to regulate the flow better. That meant I had to have gate valves instead of ball. I'm not expecting my tank to be selected for "tank of the month" although I am very proud of most of my choices. For example, aside from the two maxi-jets circulating in the main tank, I run my entire system off of one larger pump. My skimmer requires a lower flow than most. Again, a gate valve for that was needed. Without getting too far off the subject, I guess I can only advise what I know to be objectively correct. Staying objective is a tough committment to hold in reality. I can now tell you not to have a plexi-glass main tank...a shallow sand bed is just fine if you want to see a sandy bottom...a refugium is very desirable...an Aqua C skimmer makes a lot of sense...growing acroporas is best left to others who have a deep pocket and a chiller (I choose to just leave some things in the sea)...and a UV positively has helped my water clarity and fish skin condition. The rest I am still learning....

[staticfishmonger]

i agree with that with only a few differences in the approach. i have learned to love and even recomend acrylic aquariums, i have had 3 total glass tanks all of which at some point leaked. i have helped maintain other friends glass tanks all of which at some point leaked. i finally got an acrylic and have never been happier. you do have to be a little genteler with cleaning, but the advantages out weight the dissadvantages at least for me anyways. i have also learned that the skimmer is not the place to go cheap. i went euro reef and it was a pricey skimmer, but i am very pleased with its silent operation and extreme performance. as far as the uv goes i think i will keep it around and if an issue arrises i may start it up and do a little experimenting with it.

[crrichey]

If you are worried about its abilitly to kill ich, you could always run the uv before your skimmer, and then run ozone on your skimmer. Nothing is going to live through that! :D

[puzzlenow]

I agree, my UV has helped me control my ICH, but the therory is that is does not help with the prevention of ICH.

BUt let me tell you, I used to get out breaks quit regularly (I guess I never fully got rid of them), but since my UV, I rarely see any ICH spots. Yes, once in a while I might see a dot on a fish, but it falls off and never comes back.

I guess I am just lucky.

[jbanks]

I agree with the experts when they say that a UV will not cure ich because of its nature however, for me I have to agree with Puzzlenow. I too was having a really bad ich outbreak and the first thing I tried after desperation set in was Chem Marin's Stop parasite( Basically a really potent pepper concoction). My 40w UV arrived right after my 5 day treatment of Stop Parasite was complete. I hooked it up and going on three months later, not only did two of my fish, which at the time looked like two crack heads looking for their next fix recover but I have added fish since and have had no problems. I don't know what it was- the chem marin or the UV and frankly I don't care at this point. All I know is the UV stays. Oh, and by the way- my corals are doing great!

[AnAnemone]

IME the UV also seems to help stabilize conditions overall. My observations may be superstitious, but after it's addition, the tank's parameters in general became more even.
As for the occasional spot or two on my fish, with or without the UV they always go away, but with it they hardly appear at all.
I rotate one unit between 3 tanks.

[JVHam]

I am not sure of the scientific benefits but I lost 4 fish to a diatom outbreak and after adding a 9watt uv sterilizer to the 26 gallon tank and doing water changes 3 times over a 1 week period and adding a Sally Lightfoot Crab, to get rid of some hair algae, the outbreak was gone. Since then I have never had a problem with diatoms.
Just my 2 cents.

[Snailspace]

"Crack head fish"...now that's a new one! Ha. The UV, IMHO, is as important as refugium algae.

I think I will modify my Acrylic statement. Having had both (alternating), I think I will keep acrylics. They DO have great benefits against leakage, strength, weight, clarity but actylic is softer. My (newest) suggestions are get cast acrylic (slightly harder than extruded) if possible...be gentle and patient when cleaning...and just plan on replacing it more often. I used to think the tank was expensive...

Regarding "cheap" skimmers, my Aqua-C is not cheap. It works very well (but my tank doesn't need much skimming nowadays). The important part is that Aqua-C requires far less GPH than others to operate. I don't need a separate pump to run it. Therefore I use a single, larger pump to run skimmer and return. Pretty economical and simple if you set it up right. As I see it, EuroReef is really not a great skimmer. The beauty of it is in it's pump's chopping action and aeration. I don't need a second, proprietory pump to run mine. I know EuroReef is good. Mine, I believe, skims just as well without locking you into only one pump setup. Just an an opinion.

[jtermini30]

Interesting convesations o this UV topic. I am in the process of setting up a 120 and have a 'spare' UV system from another application and have not made a decision to use it. Only one time in this discussion did I read where the unit should be place as respects to the flow, someone recommended prior to the skimmer. I was thinking of installing it on the return. Not sure what is most appropriate.

I recently wet to a marine store in New Hampshire that the entire system was designed by the New England Aquarium and as I remember the UV system on both the fresh and marine systems were installed on the return.

Any thoughts?

[Bomber]

jt

Put it on it's own loop. Makes regulating the flow easier. Makes shutting it off to service it easier. etc etc You don't have to shut off all the other stuff.

[jbanks]

I totally agree with Bomber.... At times you may want to reduce your flow for a higher kill rate and being on a separate loop really makes maintenance a lot easier.


Is your 120 a new setup from scratch or are you moving another tank over? I f it is from scratch, you may wan to let your bacteria colonize for at least two months before you start running the UV. Bomber..... Your thoughts....

[Bomber]

Won't have any effects on the bacterial cycle.

[Snailspace]

I don't do everything right, but the beauty of my system has proven to be the simplicity (fewer pieces) and sectional design (separating areas by function with repairs in mind). So I agree with having the UV on a separate loop. Mine is in-line going to my fuge. It is does not do it's killing after the fuge which adds beneficials to the water. There is something to be said about the water ultimately being...the water. It's all one big soup. But I think you can make good choices and improve the effeciency of the components. This means maybe you can get away with a smaller UV than suggested.

My main pump (Mag18) is oin the center of my sump. It pumps directly vertical into an inverted Tee header. Each leg of the Tee has a GATE valve. The top leg goes to tank return. The left leg goes to skimmer. The right goes to uv and ultimately fuge. After a 1/2 day of watching and throttling flows, I was able to balnce flows appropriately to all destinations. I tie-wrapped the gate valves to mark the top positions as a reference and have left them there ever since. The only exception is the UV/fuge line.

When I shut all pumps down for feeding, the flow drains into my sump. This causes a few bubbles to enter the UV line. Bubbles around the UV causes hot spots. You have to bleed the bubbles out. So when I turn pumps back on, I open the UV/fuge gate valve 1 turn for about 15 secs. to purge it of bubbles. Then I return it to it's normal position and close the cabinet.

One caution, my UV is an Aqua brand (8w) on my 150g. Both inlet and outlet holes are on one SIDE of the UV. I wanted that. If mounmted horizontally with inlet/outlet holes faces up, any residual bubbles tend to collecv in top of housing, not around bulb.

The much lower than recommended 8w is run most all the time at a slow flow of about 10-15gph. I'm not sure of the flow. It's a "refugium flow"...not to rapid, not too stagnant. Manufacturer recommends not a bunch of on/off's as it can shorten bulb life and to not run thiung without flow for more than 30min.

If I knew how to prepare and insert a picture, I wouldn't have to talk so much. Help.

[Pyrrhus]

i just picked up a 9w turbo twist UV to combat a Phytoplankton outbreak in my tank(the glass would literally be covered in under an hour with phyto and i could barely see the animals in the tank) within one day of installing the UV the water was crystal clear. im a believer of UV sterilization in any tank.

[CrocoDillon]

Originally posted by SAT
The use of UV to prevent or cure Ich (Cryptocaryon) and other diseases is controversial... There are published studes that have actually proven, through mathematical analysis and experimentation, that it is impossible to use UV to cure Ich in a closed system.

Maybe (just a thought), the UV doesn't cure the ich, but neutralices stinging cells etc. Tangs probably are sensitive to those stinging cells, and with UV, their skin don't get stinged all the time so they can built up resistance against ich.

I got this idea when I read a topic about how much easier it was to keep Tangs ich-free back in the days we couldn't keep corals. No corals means no stingin cells in the water.

[suthrnmn]

Im running 40watts on my 120 reef. I used to keep a lot of tangs. It definately helps with the ich. It will also help with the algae and general water quality. Heat was not a problem for me, chiller in use 1/3hp. They do require right much work to keep clean, but, if you get straight muriatic acid from hardware store clean up is very fast just be sure you are well ventilated as the acid will "smoke" as it cleans and it will hurt you if you breathe it. I would recommend it esp if you have one laying around. As far as killing the good stuff, my tank is now dominated by some pretty fragile sps, I dont have but one tang left and if I can catch him he s gone to. Hope this helps, any ?s drop me a note. Ron

[FishyMel]

I use my UV on the return. It is actually designed to be plumbed into the return line. I have found that it does not stop ich from attacking but it cuts down the severity and duration of the illness. I am starting up a new tank right now and am not quarantining. The new fish will break with ich a few days after I add them but the UV keeps it under control so it doesn't spread to the healthy fish and makes a shorter illness for the new fish too. I haven't lost a fish yet and I have acclimated 6 fish this way.

[Phoneguy982]

Finally a UV thread...I had posted one and got no replies. I just bought the 18w Ultra twist UV for my 150. I plan on using my cascade power filter with carbon and place the UV inline of the return.(flow rate is 300gph) I agree that it won't CURE ich but it will prevent outbreaks. Just that alone has me sold. For $99 off e-bay it will save hundreds of dollars of fish from dieing. (when I finally get some) In the long run it's worth it knowing it helps keep the tank looking better and keeps it healthier. Isn't that the point of adding equipment to our tanks...the health of our livestock?

[flatzboy]

I love uv sterilizers even on reefs. My dad bought a monster 36 watt coralife turbo twist for his 75g. reef and it works excellent, we have never had ick or alqea blooms and if you think your water is clear know then add a uv and what a difference. I'm actually thinking of adding a 9 watt to my 46g. bow front. And the bulbs seem to be good for about 12-14 months and then you start seeing more algea and you know its time to go. Besides the bulbs for the 36 watt one can be bought of ebay for about $18 ans thats seems to be nothing compared to all the other exspensises in the marine aquarium hobby. But everybody has there own a opinion but I would say get one.

[Masoch]

Originally posted by Phoneguy982
Finally a UV thread...I had posted one and got no replies. I just bought the 18w Ultra twist UV for my 150. I plan on using my cascade power filter with carbon and place the UV inline of the return.(flow rate is 300gph) I agree that it won't CURE ich but it will prevent outbreaks. Just that alone has me sold. For $99 off e-bay it will save hundreds of dollars of fish from dieing. (when I finally get some) In the long run it's worth it knowing it helps keep the tank looking better and keeps it healthier. Isn't that the point of adding equipment to our tanks...the health of our livestock?

300 gallons of water / hour through an 18 watt UV won't even give ich a nice suntan. The flow, just estimating from my 9 watt and what I've read about it, should probably be in the range of 80 GPH, maybe even lower.

The other thing I've read is that, if you really want to control ich with a UV, you should be looking at, roughly, 1 - 1.5 watts / gallon of total system volume with 4 - 5X tank volume turnover. Ich's a relatively large parasite, and TurboTwists were made for nuking relatively small algal spores and bacteria.

[jbanks]

I agree with the particle size of ich being larger however, many of the companies that design consumer grade UVs support that their products can help control parasites. The proof is in the pudding for many others including myself and it's really simple. Before adding my 40watt Aqua Ultraviolet on my 120, I had ich. After adding it. I haven't seen ich and ich hasn't seen me :D I have read the post on 1 - 1.5 watts X 4 - 5x turnover in water volume as well and I think that may be some serious overkill. I think we can all agree that we are not eradicating it. We are simply bringing the numbers down to a level where the fish have a fighting chance and can build some immunity.


If I had a UV that powerful (based off the calculations using 1.5 watts/gallon= 180Watt UV), I would be afraid that my family would somehow be affected and come out like the Fantastic 4 after passing through the cosmic gamma rays :)

[toccata]

Here is another case "for"; I had bought a juvi queen, didn't know at the time the fish came from Brazil. This LFS I guess didn't medicate their tanks (I only buy fish from 2 sources, both of which treat their tanks) this place I never bought fish from before (just supplies). The queen as I later discovered had brooklynellosis and also found this to be a common problem for fish coming from Brazil.

At the time I didn't have a UV, but quickly added one along with raising the temperature in the tank. I lost only 2 fish from this highly contagious parasite. The queen, and the other fish lost was a butterfly. The tank was a FOWLR. Needless to say the UV was kept in place. I don't medicate my tank and rarely ever needed a quarantine tank or could justify the cost of one.

Tank has been up for almost 4 years. Only had one other incident were ich started to appear, this was due to temperature swings. The ich was also quickly taken care of by feeding with garlic extreme and raising temp. No losses.

Hope this helps...

[Julio]

I had a UV sterilizer sitting around and i hooked it up last week and let it run for a week to see if there would be any difference in my water clarity or anything else, but now that i took it back off i am noticing a lot of cyno starting to creep up and all the water parameters and feeding regiment has been the same, but i am stikking without anyway since i didn't see any diffence with it on.

[jbanks]

Wow... That's interesting that you started seeing Cyano after you removed it... After my tank was set up about 2 months, I started noticing Cyano fo the fist time; first in my sump, then in the Tank itself. I added my UV and a Tunze around the same time and after about a week, the Cyano in the Tank, which started getting pretty bad on the substrate begin lifting off the substrate and floating at the top where I was able to remove it easily. I still see very small traces in the sump, but no longer in the main display.

My water was pretty clear before I added my UV. At the time it was added, I was more concerned with how it seemed to help with parasites and bacterial infections attacking my fish.

[TwoValveKid]

As long as they are flowed correctly. (much what has been said before) they work great. Every single one that ive seen sold to people as long as they are FLOWED CORRECTLY swear by them.

[Bomber]

Two quick points.

Originally posted by Masoch
if you really want to control ich with a UV, you should be looking at, roughly, 1 - 1.5 watts / gallon of total system volume with 4 - 5X tank volume turnover.

You can't go by wattage. There are five different bulbs sold to the hobby. Every thing from NO bulbs to HO bulbs.

Originally posted by toccata
At the time I didn't have a UV, but quickly added one along with raising the temperature in the tank.

You do not want to raise the temp. Raising the temp speeds up the life cycle of the parasite, lowers O2 levels, speeds up the metabolism of the entire system and every thing in it.
If you're UV is marginal, which most hobby UV's are, raising the temp can be counter productive.

[bulldog12]

Ok here is my personal experience so far. My aqua 57 watt uv filter has been up for about a month now. Before installing any new fish I placed in the tank would die in about a week from ich. I let the uv run for about a week and added fish. So far no fish has been lost or shown any signs of ich. All are healthy. IMO uv filters are a must.

[bulldog12]

Oh and my water is clearer than ever. So I am a happy customer.

[Masoch]

You can't go by wattage. There are five different bulbs sold to the hobby. Every thing from NO bulbs to HO bulbs.

Hey, I did say "roughly" :)

And the guesstimate of a watt / gallon seems to hold for the Turbo Twist, given their manual. And, since most manufacturers fudge the potency of their widgets (at least in the cheapie range) ...

Of course, the best thing to do is to read through the manual and contact the manufacturer and find out the correct combination of wattage and flow for your combination of tank and UV.

[toccata]

Originally posted by Bomber
Two quick points.

You do not want to raise the temp. Raising the temp speeds up the life cycle of the parasite, lowers O2 levels, speeds up the metabolism of the entire system and every thing in it.
If you're UV is marginal, which most hobby UV's are, raising the temp can be counter productive.


This is exactly the point of raising the temp, speeding up the lifecycle of the parasite. Temp is raised slowly, and since the uv only kills free swimming parasites it will ensure the fish are less at risk. Lowering the salinity/SG also helps. This may not be such a good idea for a tank with lots of corals and inverts but for a fish only would not be a problem. I agree the O2 levels will drop, but if your using a wet/dry with bioballs and a skimmer, the tank is more than likely already saturated.

[Bomber]

You do not want to raise the temp when you are treating for parasites with UV.

Do you want to end up with more parasites in the water than the UV can kill and increase the chances that more parasites will find the host before the UV finds them?

or do you want to lower the temp, slow down the metabolism and reproductive rate of the parasite - and give the UV a better chance of finding the parasites before they find the host again?

[bulldog12]

Oh man I love these uv topics. :p For the most part anyone that has never had one say they are a waste of money and anyone that has a good one loves it.

[Phoneguy982]

Originally posted by Masoch
300 gallons of water / hour through an 18 watt UV won't even give ich a nice suntan. The flow, just estimating from my 9 watt and what I've read about it, should probably be in the range of 80 GPH, maybe even lower.

Luckily I can control the flow rate and slow it down to 50 gph or less if I wanted. The reason it is effective is because it spends more time in the chamber spiraling around the bulb instead of flowing straight through.

[gregb]

I think UVs are cruel.

[bulldog12]

Originally posted by gregb
I think UVs are cruel. :lol:

I hope this comment is a joke.:lol:

[jbanks]

You and I both Bulldog :)