UV Sterilizer?
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I have a novel!
ok as far a guy who has nothing but tangs in his tank ...an a uv on it ..aside from heat issue ...(i have seen none ) i think it does help with clear water ..as far it being a cure-all ...it is not...my purple still gets ick...it is a do you want it on your tank or not ..i like it .i use it ...would i tell someone to run out an get one no...its a matter of if you want it get it ...if you buy one an dont think it works unplug it .it's just like anything out there ...try it if you dont like it sell it....jmtc..:lol2: </em>
I turn my on from 10pm to 7am and have a great results so far. No ick, no hair algea, tank looks crystal clean and no dead corals or fish. Does add heat which means my heater has not come on all winter. Temp has stayed at 78. I will not run it in the summer do to the heat factor.
I believe the tank that he's questioning putting a UV on is a 30gallon tank. IMO, a UV will definitely increase the temperature of a 30gal. Undoubtedly. I based my heat comment on the assumption that he was going to put it on the tank he's in the process of setting up. In a 400gal system, a UV IS still adding heat, but there is also a lot higher cooling potential in a system that large... even with surface area alone.
Opinion's dont normally translate into a thriving tank.
The (former) Engineer is glad the things we need in life were designed on facts, tests,experimentation, and good ole common sense.
dont think an opinion, or 2 cents is gonna keep water in that one more tank ya gotta have. but if you believe it will ~ May the force be with you
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:aww: Ok. Sure. My opinion was formed from lots of reading, other people's experiences, common/basic understanding of science and how things work, and first hand experience with a 46g bowfront tank at my office. My boss (with too much money and zero saltwater experience) had a LFS set up a "fish tank" for me in my office. I asked for a saltwater tank. Next thing I know he has bought all kinds of junk and some kid is setting it up the following day. Anyway long story but the LFS sold my boss a UV system. They told him that he needed it.
Ok... have a nice night.
Still friends? :cheers:
:thumbs:
Ok... have a nice night.
Still friends? :cheers:
:thumbs:
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Tony, No i'm talking about my 75g. I don't think I will be getting one because of the heat issue. I already have a problem with that.
I tried to read up on this, but the lit is pretty vague or VERY technical. From my impressions, it seems UV bulbs don't produce that much heat as there spectrum is isolated to a very narrow band. Some heat will be transfered, but not sure if it is enough to raise the temp significantly. I think the UV bulbs are rated on wattage they consume not heat they give out. So a 25w UV bulb could easily produce as little as 5w heat which would be pretty inconsequential.
This is all theory mind you from the few good pieces of info I have managed to scavenge.
The other very interesting UV discussion I ran into was about contact time for organinc disruption along with the amount of UV needed. You need a mighty big UV to do just a 120 gallon tank effectively. Seems the manufactorers rate the bulbs about 5-10 times more effective than they actually are. Also, UV bulb frequency is very important as some critters are outright immune to even slight variations in the UV spectrum. You will kill one algae with one bulb, but another will go right on through. Parasites are even harder to squash as they require long dwell times and are also resistant to various UV spectrums.
OK nose back in book and see what else I can dig up.
This is all theory mind you from the few good pieces of info I have managed to scavenge.
The other very interesting UV discussion I ran into was about contact time for organinc disruption along with the amount of UV needed. You need a mighty big UV to do just a 120 gallon tank effectively. Seems the manufactorers rate the bulbs about 5-10 times more effective than they actually are. Also, UV bulb frequency is very important as some critters are outright immune to even slight variations in the UV spectrum. You will kill one algae with one bulb, but another will go right on through. Parasites are even harder to squash as they require long dwell times and are also resistant to various UV spectrums.
OK nose back in book and see what else I can dig up.
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Yes Cameron... you have to change them frequently because they loose efficiency. Recommended to change them every 6 months. I know some that buy 2 times too large of a unit to put into service so that they think that they can stretch out the bulb changes. Again the costs and drawbacks of UVs just dont seem worth it to me. I am feeling The Force. Thank you Bro. 
Cameron I have never met you, look forward to it, but I do read a lot of your posts. It seems that the great majority of the info you give, you will research it through a couple sources to find out both sides, then you share what you have read and then your conclusions to it.
You are truly a credit to the club.
I would say read up. There is good info out there all over the place. Then it's your decision to use one or not. I would suggest trying one at some point just to see. Over the years I have used them on displays and hospital tanks. I still use one on a hospital tank but not on the display. Benefits didn't outweigh the costs for me. Maybe for you they do.
Bottom line is if you want to try it try it. It's by no means neccessary but it also is not going to nuke the tank or anything detrimental like that. So experiment, try, read, then decide.
If the added heat matters or not is totally dependant on your system, size of sterilizer, etc. so no one can unequivocally state in generaly it will or won't be a problem. It will add heat but it may not matter or effect the tank enough to notice. It depends on lots of factors. It definitely kills some bacteria, algea, etc (both good and bad). Whether that is a good cost/benefit relationship is also a big question mark and again probably dependant on your system.
Ozone is largely the same. It does break down the agents that cause yellowing so your water will most likely be clearer. It does effect skimming (some claim good, some claim bad) and it does break down organics. It helps ORP. It does kill some pathogens and again is not discriminate between good and bad. It does require precautions from overdosing or letting it get ionto the air. Again over the years I have done both with and without. Right now I'm without and my tank is crystal clear and everything is rocking and rolling but I have used it on tanks before where there was some yellowing and it clears it up quickly. I'm still undecided on the skimming thing but I have seen it help others with disease issues so there are benefits. So again it's a cost/benfit equation that is going to be unique to you and your system.
Peace Out
Bottom line is if you want to try it try it. It's by no means neccessary but it also is not going to nuke the tank or anything detrimental like that. So experiment, try, read, then decide.
If the added heat matters or not is totally dependant on your system, size of sterilizer, etc. so no one can unequivocally state in generaly it will or won't be a problem. It will add heat but it may not matter or effect the tank enough to notice. It depends on lots of factors. It definitely kills some bacteria, algea, etc (both good and bad). Whether that is a good cost/benefit relationship is also a big question mark and again probably dependant on your system.
Ozone is largely the same. It does break down the agents that cause yellowing so your water will most likely be clearer. It does effect skimming (some claim good, some claim bad) and it does break down organics. It helps ORP. It does kill some pathogens and again is not discriminate between good and bad. It does require precautions from overdosing or letting it get ionto the air. Again over the years I have done both with and without. Right now I'm without and my tank is crystal clear and everything is rocking and rolling but I have used it on tanks before where there was some yellowing and it clears it up quickly. I'm still undecided on the skimming thing but I have seen it help others with disease issues so there are benefits. So again it's a cost/benfit equation that is going to be unique to you and your system.
Peace Out
I understand what you're trying to say, but I can't agree without more evidence.
Energy going into the system must equal the energy leaving the system. Period. The http://en.wikipedia.org/wiki/First_law_of_thermodynamics">First Law of Thermodynamics</a> says so. :)
[QUOTE=]I think the UV bulbs are rated on wattage they consume not heat they give out.[/QUOTE]
No, UV bulbs, powerheads, lights, and everything else electric are rated based on the power they consume - 10watts, 36watts, 400watts, etc. It's true that, in this case, the UV bulb will change that electricity into UV light by whatever mechanism, and it might do so at whatever efficiency. However, because of the first law of thermodynamics, we know that energy must be transferred- if 36w of energy goes into that UV sterilizer, 36w of energy has to come out as something else.
Energy manifests itself in only so many [IMG]http://en.wikipedia.org/wiki/Energy#Different_forms_of_energy_and_their_inter-relations">known forms</a>, so it must exit the system in one of those forms: gravitational, electric, magnetic (which includes light), thermal, chemical, elastic, or nuclear. I don't think your UV sterilizer is generating gravity or creating a nuclear reaction, so I'm guessing it's going to be thermal. Thus, whatever the wattage rating of the UV bulb is going to be, it's the same as adding the same wattage rated heater, plus or minus a bit for efficiency differences.
In the same vein, I finally had to conceed the same thing was happening with powerheads. It doesn't make sense initially, but think about it the same way, and there's no way around it - they've [B]got[/B] to add the their wattage to the tank. If a Tunze uses 65watts, it adds 65watts to the tank. It took me a while to realize that this had to come from friction of water against the walls of the container - otherwise, the water would turn forever. Interesting stuff.
I'm open for debate on this one - it took me a good month to come to this conclusion by reading a bunch of stuff, but I feel pretty confident this is all correct.
Chris, I'm not disagreeing but help me understand. A powerhead should convert the electrical into mechanical (spinning the impellor). Now it doesn't do this 100% efficiently and some is converted into thermal (aka heat)
Same with a light, UV or otherwise. It takes electrical converts to a radient but that conversion is inefficient and produces heat?
So the efficiency would play a big part in it so different powerheads of the same wattage could be at different efficiency levels for the same wattage and same with lights. Which in turn would change the thermal part produced.
A heater is meant to convert electrical to thermal. Fortunately this is fairly lossless (i.e very efficent conversion) butagain there is some loss occuring.
Correct or no?
Wow can we highjack a thread!
Same with a light, UV or otherwise. It takes electrical converts to a radient but that conversion is inefficient and produces heat?
So the efficiency would play a big part in it so different powerheads of the same wattage could be at different efficiency levels for the same wattage and same with lights. Which in turn would change the thermal part produced.
A heater is meant to convert electrical to thermal. Fortunately this is fairly lossless (i.e very efficent conversion) butagain there is some loss occuring.
Correct or no?
Wow can we highjack a thread!
Yes, inefficiencies are always present- more for some devices (metal halide lights) and less for others (impellers). However, the total amount of energy in the system must remain constant - energy http://en.wikipedia.org/wiki/Conservation_of_energy">cannot be created or destroyed</a> - only transferred.
Let's use the case of lights. I've read that metal halide light bulbs can range between 2-5% efficient (horrible... compare that to LEDs which are ~95% efficient). Anyway, assume we have a 250w metal halide, and that it's 5% efficient, and that it actually draws 300w from the wall (based on my measurements using your PFO magnetic ballast and my kill-a-watt meter):
300w total energy consumed
- 50w ballast heat
- 5% efficiency = 12.5 watts converted to light energy
- 95% leftover = 237.5 watts of heat energy
Note that the numbers are all approximate. In the case of our bulb here, 237.5+50w = 287.5watts of electricity is converted to heat, and the remaining 12.5 watts is light. Then the question becomes - what happens to that light energy? Again, since it doesn't become gravitational or any other of the energies I pulled from above, it becomes heat and (unless it's underwater like a UV bulb) it's transmitted either into the water or the room.
In short, it all becomes heat again at some point. This wouldn't hold true if we were dealing with different systems - it just happens that we work with only a few forms of energy in our aquariums.
In the case of the powerhead, we could do the same conversion. Let's assume that it's 98% efficient (I have no idea what the actual number is) and that it consumes 50 watts.
1 watt is converted directly to heat
49 watts of that energy is converted into mechanical force. Because the water stops spinning in the tank eventually, we can assume there's a frictional force at place (between the water itself and the walls of the container), and thus the rest of the energy is eventaully converted to heat.
It's conceivable (although not likely) that the energy could manifest itself in other forms, but until we see light emenating from around the powerhead, we can safely assume it's heat.
Again, I can be wrong, but I do know that we can't get around the Law of Conservation of Energy - whatever energy goes into the system must come back out, and it's almost always as heat in our aquariums.
Let's use the case of lights. I've read that metal halide light bulbs can range between 2-5% efficient (horrible... compare that to LEDs which are ~95% efficient). Anyway, assume we have a 250w metal halide, and that it's 5% efficient, and that it actually draws 300w from the wall (based on my measurements using your PFO magnetic ballast and my kill-a-watt meter):
300w total energy consumed
- 50w ballast heat
- 5% efficiency = 12.5 watts converted to light energy
- 95% leftover = 237.5 watts of heat energy
Note that the numbers are all approximate. In the case of our bulb here, 237.5+50w = 287.5watts of electricity is converted to heat, and the remaining 12.5 watts is light. Then the question becomes - what happens to that light energy? Again, since it doesn't become gravitational or any other of the energies I pulled from above, it becomes heat and (unless it's underwater like a UV bulb) it's transmitted either into the water or the room.
In short, it all becomes heat again at some point. This wouldn't hold true if we were dealing with different systems - it just happens that we work with only a few forms of energy in our aquariums.
In the case of the powerhead, we could do the same conversion. Let's assume that it's 98% efficient (I have no idea what the actual number is) and that it consumes 50 watts.
1 watt is converted directly to heat
49 watts of that energy is converted into mechanical force. Because the water stops spinning in the tank eventually, we can assume there's a frictional force at place (between the water itself and the walls of the container), and thus the rest of the energy is eventaully converted to heat.
It's conceivable (although not likely) that the energy could manifest itself in other forms, but until we see light emenating from around the powerhead, we can safely assume it's heat.
Again, I can be wrong, but I do know that we can't get around the Law of Conservation of Energy - whatever energy goes into the system must come back out, and it's almost always as heat in our aquariums.
I have two UV's one running and one not. My fish only has a 18 watt Coral Life turbo twist model that works O.K.. I have a 57 watt Aqua that I usually run on my reef, however, the bulb went out about 6 months ago. It is very effective and was run 24/7. Since I have not put anything new into the tank (other than corals) I have not replaced the bulb. I do have all kinds of pods in both setups. Once a year I have a pool cleaner (acid) that I use to clean the crystal glass.
I do know THAT THE AMOUNT OF WATER FLOW IS THE MOST IMPORTANT element in the use of a UV. If you have too much it is ineffective, too little flow-you get a lot of bacteria kills, but also a lot of rise in water temp.
I wouldn't run my fish only without it, but the reef has a full circle of life....I don't think you need one after your setup is stable and parasite free.
I do know THAT THE AMOUNT OF WATER FLOW IS THE MOST IMPORTANT element in the use of a UV. If you have too much it is ineffective, too little flow-you get a lot of bacteria kills, but also a lot of rise in water temp.
I wouldn't run my fish only without it, but the reef has a full circle of life....I don't think you need one after your setup is stable and parasite free.
It has been a while since I took a EE course so bear with me here and correct me where I am wrong (I could be very wrong).
Heat from a light bulb is generated via the infrared spectrum and the filament getting scorched and transferred to the glass. Most bulbs including UV produce this infrared lighting. However because florescent bulbs collide the electrons with mercury to produce UV light little infrared light is produced. Basically UV bulb is actually a fluorescent bulb without the phosphorus coating that blocks the harmful UV rays.
I hear what you are saying about energy being converted but not all light becomes heat. Various spectrums produce more heat than others. This is why a 5w florescent bulb can produce the same amount of visible light as a 60w incandescent bulb.
There may be some jump in my logic since I am no physicist and we are getting dangerously into this territory. Maybe a 36w florescent produces as much heat as a 36w infrared bulb, but I don't think so.
Heat from a light bulb is generated via the infrared spectrum and the filament getting scorched and transferred to the glass. Most bulbs including UV produce this infrared lighting. However because florescent bulbs collide the electrons with mercury to produce UV light little infrared light is produced. Basically UV bulb is actually a fluorescent bulb without the phosphorus coating that blocks the harmful UV rays.
I hear what you are saying about energy being converted but not all light becomes heat. Various spectrums produce more heat than others. This is why a 5w florescent bulb can produce the same amount of visible light as a 60w incandescent bulb.
There may be some jump in my logic since I am no physicist and we are getting dangerously into this territory. Maybe a 36w florescent produces as much heat as a 36w infrared bulb, but I don't think so.
Your understanding of a flourescent/UV bulb is the same as mine. I agree with the assertion that some wavelengths of light are radiated heat - namely the IR side of the spectrum (as opposed to the UV side).
Ok. Then for discussion's sake, can you suggest where the energy goes? If the law of conservation of energy doesn't apply, then please explain why that may be. The light energy can't just disappear... if it doesn't become heat, what does happen? You could also argue (in opposition to other types of energy) E=mc^2, but we'd have to have some additional mass build up somewhere (albeit an immeasurable amount).
I'd bet that it would. I'm not sure how to best test it, since it'd require a completely closed environment to leave them in, but it'd be an interesting experiment...
Good discussion. :up:
I am beginning to think you are correct partially anyway. My head is spinning trying to understand how it works. Eventually all light is absorbed and becomes heat (maybe haven't quite solidified that answer yet) so if light can't exit a UV sterilizer it eventually becomes heat from the various surfaces. Infrared is just very easily converted to heat and absorbed almost instantly so it has the appearance of being related to heat, but as all light energy has to go somewhere all light waves produce heat. It is just that different waves are absorbed easier. Eventually all light is absorbed so it is equally transferable to heat.
Now that said, I am trying to understand how the wave length actually effects heat. Apparently the shorter the wavelength the longer it takes for it be absorbed and converted. This duration allows more time for a surface to transfer heat away into the air, water and the surface material itself. So UV would eventually heat up objects as much as infrared, but would allow a longer time for the object to transfer its heat.
Here is where I go off the tracks trying to understand UV lighting. The UV emission is "absorbed" by organisms causing them to break down on an atomic level. Two things I haven't worked out. Does this atomic breakdown convert the energy of the light into a form other than heat by shuffling electrons? Second, does the object absorbing heat up and take some time to radiate its heat into the aquarium? There is also a "loss" depending on the spectrum produced. It takes more energy to make blue light than red.
Lots of questions and so few answers easy to come by. Need a physicist in here.
Oh yeah, good discussion. I tried to stay out of it for a while, but I just couldn't help myself.
