eaf
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Post by eaf on Oct 26, 2015 14:35:52 GMT -5
I'm asking these questions here as per the recommendation of customer support... I've read a lot of things on UV sterilization at www.americanaquariumproducts.com and about how Vectons are pretty much the best bang for the buck on the market. But despite pretty extensive info, some things seem controversial to me, hence this thread. First, in a lot of places the emphasis is made on how .4cm water gap makes Vectons superior to other sterilizers, especially that Turbo-twist. But is the gap really 4mm in Vectons? Consider Vecton 2 200 for instance. Its quartz tube's outer diameter is 19mm while the inside diameter of PVC housing is what I think 40mm. Support says 50mm, but I think they either meant the outer one or may be mistaken, because if 50mm is indeed the inner diameter, then things are even worse. So, (40-19)/2=10.5mm is the actual thickness of the water layer around the quartz tube. 2.5 times more than .4cm. Where am I miscalculating things? Second, right now as far as Vectons are concerned I'm debating between pretty much two things: getting Vecton 2 200 or 400 (or getting Vecton 2 200 and putting a better ballast and higher power UV). So, thinking that I have all the measurements, I decided to see, which one would fry things better... That would depend on two things: the dwell time and radiation power per unit of surface area expressed as W/cm2. I see that in many pages AAP tries adjusting dwell time in order to take into account water thickness or distance from the bulb, but I won't. I'll keep things clearly separate. Time is time, power is power. Yes, after travelling through thicker water or even after moving farther from the bulb UV power per unit of surface will be reduced, but it has nothing to do with time. So, let's compare the two. The inner PVC diameter is 40mm in both cases, quartz tubes are 19mm and 29mm for 200 and 400 models. Vecton 2 200: Effective run length barb-to-barb is 7" Area of cross-section is proportional to (40*40-19*19) T5 Lamp power is 9W (12" long) Vecton 2 400: Effective run length barb-to-barb is 13" Area of cross-section is proportional to (40*40-29*29) T8 Lamp power is 15W (17" long) The ratio of dwell time between the two units for the same flow rate is given by 13/7*(40*40-29*29)/(40*40-19*19)=1.13. It's proportional both to the path length and to the cross-section area. The increase in Vecton 2 400's length is negated by the smaller area making water move faster along the longer path. But perhaps the 15W lamp will make things better? Not by much because 15W are now also spread over longer 17" rather than 12" 9W. So, the ratio of W/cm2 between the two bulbs at the same distance from the bulb is (15/17)/(9/12)=1.17. So even though 15W bulb is 1.6 more powerful than 9W, the effective energy per cm2 is only 1.17 more. Multiplying the two we get a 1.13*1.17=1.3 - this is how much better Vecton 2 400 seems compared to Vecton 2 200. But is it still? Remember that in Vecton 2 200 water is running closer to the bulb: it starts at 19mm diameter compared to 29mm of Vecton 2 400. So, the surface area that the bulb's power should be divided upon in order to get energy flux is 19/29 less in Vecton 2 200 making it 29/19=1.5 better! 1.3/1.5=0.86 is how much Vecton 2 400 appears "better" in my calculations than Vecton 2 200. It's actually worse! I've taken into account: 1) Differences in bulb power 2) Differences in run length 3) Differences in cross-section 4) Differences in distance from the bulb. And based on what I see Vecton 2 200 is BETTER than Vecton 2 400. Heck, I can also factor in better T5 efficiency over T8, and it will be even betterER. I can add that I can probably put a 18W bulb in it, and it will instantly double the exposure. So, what am I missing here? Why should anyone buy a 400 model over 200?
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eaf
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Post by eaf on Oct 26, 2015 15:27:50 GMT -5
As a follow-up question, allow me to challenge the statement on www.americanaquariumproducts.com/ saying that UV sterilizers that do not maintain a .4cm water gap are not doing a good job. UV light actually penetrates the water pretty good, at least in the part of the spectrum closer to the visible one. I thought that perhaps UVC would be different, but after some searching I found this: water.epa.gov/lawsregs/rulesregs/sdwa/mdbp/upload/2001_01_12_mdbp_alter_chapt_8.pdfThe equation of interest is on page 8-3, it defines percent transmittance of 254nm UVC through a 1cm thick water layer. For fair water quality it gives a 75% transmittance, for good 85%, and for excellent 95%. Could you please refer me to the sources that may substantiate the need for having a .4cm gap?
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Post by Carl on Oct 26, 2015 16:10:00 GMT -5
The simple answer is experiments where I used a solution of dirt born bacteria to cloud a tank, then timed the clarification process.. A better comparison would be the Vecton 300 which is 16 watts, but otherwise the same dimensions as the Vecton 200. The Vecton 400 cleared the water faster in these test, which is why I ceased selling the 300 I would also quote what I wrote in the Dwell time experiment article: "A Controlled Experiment between a Terminator 13 Watt UV Sterilizer (which is one of the best compact UV Sterilizer designs as per water contact design) VERSUS a TMC Vecton 8 Watt "High Dwell Time" UV tells the story of UVC Dwell Time:
Using a Rio 600 (200 gph), with 2 feet of 5/8" ID tubing; the dwell time inside the Vecton was 2.6 seconds, while the Terminator was 3 seconds. It is important to note that the Terminator holds DOUBLE the water volume at 20 oz. water (meaning a less efficient design with more water not within the optimal .3 cm exposure zone) versus 10 oz. of water for the 8 Watt Vecton. Keep in mind that the Terminator is one of the best designed Compact UVs, as it is noteworthy that the Turbo Twist has an even higher water volume due to even less efficient water contact design. The result is 6.66 ounces of water per second is exposed to UVC irradiation for the 13 Watt Terminator while 3.84 ounces of water per second is exposed to UVC irradiation for the 8 Watt Vecton. MORE IMPORTANTLY the results are 1.95 watts of UVC energy per second for the Terminator 13 watt versus 2.08 watts of UVC energy per second for the 8 Watt Vecton/"As for the gap, the intensity factor decreases as the light source is further. www.uvsterilizerreview.com/2009/03/uvc-watts-microwatts.htmlThe distance of 3 cm is a number that was given to me years ago by Aquatronics. Whether this is the best number, I have never found anything to counter this exact number, so I am all "ears". More importantly, & I will be blunt here is my experience. I have been using, experimenting, testing, and even building UVs since 1978. Sometimes what I found were my results were not necessarily what were the common knowledge. It was these experiments that led me to the Vecton, Aqua, and other UVs. Often what I would do is reverse engineer to find the whys of my results. So while my reasons/conclusions as to why may be off, my results I stand solidly behind. This includes use of brands you noted such as the Turbo Twist which besides ballast issues were slower yet in my clearing tests. Back to the gap, one thing I point out in my articles is the gap used in many pond and canister filters with built in UV sterilizers. Early on I found that even when flow rates were reduced, these were not clearing the ponds nearly as quickly as equivalent stand alone UVs (such as a 9 watt pressurized Tetra compared to a 9 watt Tetra stand alone UV). The only difference was the gap. It was then I was asking around as to the best gap and I was told 3 cm by Aquatronics (right or wrong). This also does not mean that anything wider is junk, far from it, just less effective as with anything with too high of a flow rate. For this reason, you will note that even the products that I sell with these features, I do not recommend for anything more than clarification (this does not mean these cannot perform level 1 sterilization, just that it would take unreasonably slow flow rates to do as such). Carl
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Post by devonjohnsgard on Oct 26, 2015 17:45:41 GMT -5
Some good points being made... a little slitting of hairs. Lot of time and effort for just one aspect of aquarium keeping. Since, the basic design is better than most of the market... would it make sense to leave it at that?
Wouldn't just make sense to get the larger unit and know you are getting the best sterilization possible?
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Post by Carl on Oct 26, 2015 18:07:52 GMT -5
In looking at your numbers several times, I think you make some good points.
However a few aspects are flawed IMO, and that is the raw data. The design of the Vectons has a deflection shield as the water enters and exits the unit. Unlike many UVs, where the hose barbs come in is not where the water leaves and exists. The design allows for the maximum use of the length of the lamp.
The other number is you are using 9 watts for the Vecton 200, not the correct 8 watts. This may be splitting hairs though on my part as Devon just noted.
The other aspect that I think is missed is the part the gap plays in intensity factor. While your formula is certainly three dimensional, I think it is more linear in its outcome missing the importance of water being as close to the lamp/quartz sleeve as possible.
I would have agree with Devon that with all that is involved, why not just get a 25 Watt Vecton 600 instead of attempting to super charge a Vecton 200? As well, I will point out quite dogmatically, that the lifespan you will get from the ballast used by any of these Vectons will outperform ANY electronic ballast. I have NEVER, in 1000s of applications replaced a single magnetic ballast employed by TMC, other than misuse (such water damage). I cannot say the same for any electronic ballast, even those used by TMC (which have still fared better than most others, most notable the Turbo Twist).
Carl
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eaf
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Post by eaf on Oct 26, 2015 19:02:31 GMT -5
Yeah, I stand corrected. It's 8w indeed, not 9w, must've confused it with another model.
There are deflections shields? Nice to know, since one of the complains about Aqua UV is that they underutilize the length of the lamp. So, recalculating the above we get:
17/12*(40*40-29*29)/(40*40-19*19)=0.86 coefficient for geometry and dwell time correction (15/17)/(8/12)=1.32 coefficient for power correction 19/29=0.65 coefficient for the running farther from the bulb correction (different quartz tube diameter)
Multiplying the three we get 0.74 - that's still less than 1, meaning the 200 model even w/o bulb upgrade gives better exposure than 400.
Experience is a great thing, it's always better than just plain number crunching but... Did you notice how you said that you were running tests with cloudy or green water? That's a big difference from what I'm pondering here. With cloudy water the penetration is not going to be at 75-95% as in that article, of course, and the thickness of the water layer becomes a significant factor. But I'm not going to use Vecton as a clarifier, am I? Clarifiers is what people tend to call lousy sterilizers like Green Machine, they serve the purpose of ridding water of green bacteria, and that's all they can do. We strive to achieve Level 1 sterilization, and here the water is already clear, i.e. clarified. So the thickness stops being a factor. Distance from the bulb still is. Btw, is it .3cm or 3cm? I think I saw .3cm in the articles. Now that I re-read them, I see there is a mix of .3cm and 3cm. So, I figure, 3cm is the threshold that should not be exceeded?
Btw, speaking of the Turbo Twist, I believe the Twist is a gimmick indeed, but not because it runs water in a thick layer. It's because for whatever reason they decided to throw it in a narrow spiral thereby speeding it up and increasing resistance. If they removed the baffles and left the volume and cross-section the same, the water would STILL stay inside the unit for the same amount of time. Except that now it would move slower w/o creating all that extra head pressure.
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Post by devonjohnsgard on Oct 26, 2015 19:41:15 GMT -5
I can follow the reasoning behind the points made and would think they are correct. The one thing that suppose to set the 8 watt and 15 watt is length of lamp and that's where I'm still a little confused, because it was ran over quickly.
How do we conclude this when head pressure is applied:
"The ratio of dwell time between the two units for the same flow rate is given by 13/7*(40*40-29*29)/(40*40-19*19)=1.13. It's proportional both to the path length and to the cross-section area. The increase in Vecton 2 400's length is negated by the smaller area making water move faster along the longer path."
Forgive me if I don't understand, but what's the reasoning behind this statement? The water moves that much quicker on a longer bulb? How if there's pressure applied to the whole system? Wouldn't the flow be different anyways? This is assuming the same gph flow?
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Post by Carl on Oct 26, 2015 20:06:49 GMT -5
The reason behind the induced clouding aquariums test is because it was simple and easy to measure and control. As per many of my articles, the main reason I became a big proponent of UV Sterilization was for disease prevention, not clarification.
My MANY observations were that certain UV designs, flow rates, etc worked better for sterilization, however you cannot measure observations. There are too many variables to testing bacteria, hence my tests with induced cloudy water.
As for the 3 cm or .3 cm, you just discovered a major weakness of mine; typing. You also caught this in my wording of the head pressure article. Even in college, I got my worst grade in typing. Anyway, it is 3 cm or less (& less is better as per the graph I provided earlier)
Carl
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eaf
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Post by eaf on Oct 26, 2015 21:49:09 GMT -5
How do we conclude this when head pressure is applied: "The ratio of dwell time between the two units for the same flow rate is given by 13/7*(40*40-29*29)/(40*40-19*19)=1.13. It's proportional both to the path length and to the cross-section area. The increase in Vecton 2 400's length is negated by the smaller area making water move faster along the longer path." Forgive me if I don't understand, but what's the reasoning behind this statement? The water moves that much quicker on a longer bulb? How if there's pressure applied to the whole system? Wouldn't the flow be different anyways? This is assuming the same gph flow? Assuming that GPH is the same, the linear speed of water in the incoming pipes is the same. When water enters filter's chamber it either slows down or speeds up inversely proportional to the ratio of the chamber's cross-section area to the cross-section area of the incoming pipes. So, the speed of the water flow is inversely proportional to the chamber's cross-section area. Time travelled T=L/V, so time is proportional both to the length of the chamber and the area of the cross-section. In fact, it's proportional to the volume of the chamber. That's what 13/7*(40*40-29*29)/(40*40-19*19) is: it's ratio of volumes.
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eaf
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Post by eaf on Oct 26, 2015 22:10:20 GMT -5
But all the numbers aside, please explain one basic thing to me... Why do we even care about dwell time in a closed-loop system? There seem to be an agreement that kill rate is proportional to the UV power and exposure time. Why do we insist that this exposure has to be as much continuous as possible, i.e. during one pass through the sterilizer. Is the damage done not cumulative, like e.g. with pilots?
Here is a couple of quotes from the link I've posted earlier:
"Research indicates that when microorganisms are exposed to UV radiation, a constant fraction of the living population is inactivated during each progressive increment in time. This dose-response relationship for germicidal effect indicates that high intensity UV energy over a short period of time would provide the same kill as a lower intensity UV energy at a proportionally longer period of time."
"The germicidal effects of UV light involve photochemical damage to RNA and DNA within the microorganisms. DNA and RNA carry genetic information necessary for reproduction; therefore, damage to either of these substances can effectively sterilize the organism."
So, once a UV photon has been absorbed and damaged one DNA, that microorganism is doomed. Absorption rate is proportional to power and time, there is nothing said about GPH. Yeah, if it's a water plant that sterilizes water on the one-way through, it's important to get decent rates, because it's the only chance they've got, but with aquaria and ongoing circulation why would anyone care? If something got missed, it will be picked up next time. In fact, run the water through the filter as fast as you can, UV is ON all the time anyway. Because if you run it too slow, who knows, perhaps everything will be killed during the first 1sec of travel, and the rest of dwell time will be wasted.
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Post by Carl on Oct 27, 2015 9:20:28 GMT -5
But all the numbers aside, please explain one basic thing to me... Why do we even care about dwell time in a closed-loop system? There seem to be an agreement that kill rate is proportional to the UV power and exposure time. Why do we insist that this exposure has to be as much continuous as possible, i.e. during one pass through the sterilizer. Is the damage done not cumulative, like e.g. with pilots? Simple from my perspective/use; The 9 watt Terminator and 8 Watt Vecton, both UVs I have used extensively, both with good results. However the results were better with the Vectonand the induced cloudy water test also showed better results with the Vecton (which the Vecton was also 10% lower energy too). Our Dwell time test is part of this explanation (as cited earlier in this thread) Carl
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eaf
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Post by eaf on Oct 27, 2015 9:56:48 GMT -5
That's not what I asked, and that's not what the Dwell time test explains. Typically dwell time calculations that I've seen everywhere start with a chart explaining which dosage (expressed in uW/cm2*s) is needed to kill a particular bacteria, protozoa, etc. And then they start putting together bulb power, dwell time, sterilizer geometry in order to arrive at the cumulative dosage that a unit volume will get after moving through the sterilizer once. Then they say: "OK, in order to achieve, e.g. 300,000 uW/cm2*s that's needed to kill Ich you have to run water thaaaaaat slow, to make sure that by the time that Ich cell leaves the chamber it will have accumulated enough" My question is basic: is this axiom (get max dosage in one pass) at all valid in the aquarium world where the water is continuously circulating through the filter? Somehow I'm starting to doubt that. One of the reasons why is the way how they seem to calculate these dosage numbers. When subjected to UV light microorganisms are getting continuously killed, and this makes sense. Light can be seen as a flow of photons, energy of each photon is the defined only by its wavelength, not by the wattage of the bulb or by surface area. If a photon interacts with electron by pushing it to a higher energy level or by pushing it away from the molecule, the bond between atoms becomes broken, if not, then not. But it's a "yes/no" event. If interaction between electron and photon has happened, the bond is broken, if not, then not, there is no in-between state with the streams of photons swinging that bond more and more like kids swing, until the electron eventually flies away. I've seen in UV papers that for each type of bacteria there are different doses listed: log1 inactivation dose, log2, etc. E.g. log1 is the cumulative dose that's needed to reduce the population to 1/10 of the original. log2 is the cumulative dose needed to reduce it to 1/100 of the original. As I saw, the dosage that is sometimes listed by UV manufacturers per certain bacteria (e.g. see the prospectus for LifeGard UV sterilizers) is around log4. E.g. compare LifeGard's listed "Killing Dose" for Salmonella enteritidis 7600uW/cm2*s with log4 dose 10000uW/cm2*s from www.trojanuv.com/resources/trojanuv/casestudies/MDW/Introduction_to_UV_Disinfection_for_Drinking_Water__European_Focus_.pdfSo, it's definitely NOT that one has to make sure that a unit volume of water needs to accumulate "lethal dosage" of radiation (as UV filter manufacturers define it) on a single pass through the sterilizer. No. As with the Salmonella above, even if that volume of water gets only a 1500uW/cm2*s on its way through, the population of Salmonella will still be reduced 10 times, not 10000 times, but it will STILL be reduced. Next time it will be reduced 10 times more, next time 10 times more again, and by the time it passes through the filter 4 times it will get the same 10000 reduction, i.e. the original log4. What I'm getting at is that it seems that if I have a "properly sized setup" that achieves log4, i.e. 10000x Salmonella killing rate on a single pass through the UV filter, and then I increase the flow 4 times, I'll STILL have the same chances of killing it. Not on the first pass, but on the fourth. But it hardly matters because with GPH being 4 times higher than in the original "properly sized setup" I'll circulate tank's water 4 times more over the same period of time. So, no matter what the GPH is, the reduction of Salmonella population WITH TIME will be the same. So, is the axiom that we should strive to achieve maximum dwell time wrong?
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Post by Carl on Oct 27, 2015 10:08:56 GMT -5
That's not what I asked, and that's not what the Dwell time test explains. We will then have to agree to disagree. I am certainly open to a better explanation of my results, but these tests and UV Sterilizer internal designs for now explain the results best. This is similar to how I came about my views as to aquarium Redox, my test results were not being explained by anything I read. Later, it has been shown that Redox reduction is important for physiology. You seem to be under the assumption that I have not read these articles/research you have pointed out,however I have read these and similar several times over the years, so I am quite aware of the points you are making, including how UVC works. So honestly I really do not appreciate your lecturing me on points I am quite well aware of. Carl
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Post by Carl on Oct 27, 2015 10:13:00 GMT -5
I will also disagree with this assumption.
If this were correct, why can one spend four 15 minute 'sessions" in the sun and not get burned, but this same person spend one hour and get burned. I will not totally argue cumulative sterilizations, as I too have found results, but not the same as with optimum sterilization in one pass.
Carl
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Post by Carl on Oct 27, 2015 10:42:19 GMT -5
In all your arguments, you are missing the point that the Vecton 400 out performed the Vecton 300. As well the Pond Advantage 30 watt with a 36" lamp had a bigger difference in sterilization abilities over a 25 Watt A than the 25 Watt Advantage had over the 15 Watt Advantage (both with 18" lamps), even though wattage was closer between the 30 and 25 watt models.
If your theories were/are correct, why did the Nektonics bulb style UV that came out in the late 70s which had poor contact time and UVC exposure fail to perform even the most remedial clarification???
As for turnover, in experiments with ponds, this is where I established difference with UV abilities (even with the same UV) between flow patterns and turn over rates. I found better results due to flow patterns that went from one end of the pond to the far side over circulation patterns that had the UV in a loop that was more one sided (even with circulation pumps to move water to the other side). Increasing turnover further improved results.
Carl
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eaf
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Post by eaf on Oct 27, 2015 10:54:00 GMT -5
That's not what I asked, and that's not what the Dwell time test explains. We will then have to agree to disagree. I am certainly open to a better explanation of my results, but these tests and UV Sterilizer internal designs for now explain the results best. This is similar to how I came about my views as to aquarium Redox, my test results were not being explained by anything I read. Later, it has been shown that Redox reduction is important for physiology. You seem to be under the assumption that I have not read these articles/research you have pointed out,however I have read these and similar several times over the years, so I am quite aware of the points you are making, including how UVC works. So honestly I really do not appreciate your lecturing me on points I am quite well aware of. Carl Where do you see me lecturing you?? I said that your time dwell experiment no matter how great it is, does not answer my question, because in way too many places there you put emphasis on dwell time (it's a dwell time test after all), and I'm questioning the basic importance of the dwell time. It's as simple as that. Take your experiment in the context of a single pass sterilization in a water plant, and it can go in a textbook, but if there is a chance that dwell time is not that relevant in aquarium with continuous circulation, the experiment is out of context. And it's not a personal attack at all. Everybody is going by the same assumptions and everybody is doing the same number crunching. I don't know whether it's because it's easier to approach it this way, or because everybody is just copying each other. Those two articles suggest a different point of view, that's all. I saw you being sure enough in going against TMC recommendation in maximum tank size for every model of Vecton (your numbers are quite higher) and you defending your point of view basically proving the manufacturer's stereotypes wrong by putting your numbers and some empirical rules together, same thing here. If there are production (as opposed to hobby) articles suggesting something that goes against common wisdom of hobbyists, that is certainly something that is worth considering. You took your time putting your numbers together (btw, still .3cm in the dwell time article), I'm taking my time understanding them. At least someone is not skipping all that logic and running straight to the answers at the bottom of the page
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eaf
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Post by eaf on Oct 27, 2015 10:57:40 GMT -5
I will also disagree with this assumption. If this were correct, why can one spend four 15 minute 'sessions" in the sun and not get burned, but this same person spend one hour and get burned. I will not totally argue cumulative sterilizations, as I too have found results, but not the same as with optimum sterilization in one pass. Carl Interesting question. Cell regeneration? While in protozoa there is just one cell that when inactivated stays inactivated and can't spawn any more? But good thinking. Interestingly, it's the sunburn analogy that sent me yesterday to look for actual UV water penetration rates. Because from experience, even if you're snorkeling or diving to shallow depth, you still get burned, despite a substantial thickness of water above.
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Post by devonjohnsgard on Oct 27, 2015 11:02:15 GMT -5
There seems to be a major disconnect on this thread, where you're actually saying Carl and TMC manufactures are incorrect. In fact, you are stating, the numbers published on something like SunSun Pressured Filter with about 2100 gph with a 13 watt UV is in fact what you want, when in fact, we have already proven these number to be poor at even clarification.
With the simple adjustment of the dwell time, using the same filter, it made all the difference in the world.
You are completely writing off the design made by professionals of these sterilizers. The point of the 15 watt vecton vs. the 8 watt is the length of the bulb and you are completely writing it off due to an increase in speed over the longer bulb. Which I do not agree with either. I might just test this, as this would be an easy test to preform. You're reasoning behind this doesn't make sense and even if there's a sight increase in flow, does it make it that much useless, that all the sudden 8 watts can bet it out?
There would be no reason for TMC to develop any of there other sterilizers/clarifiers with that reasoning.
Your basically saying with the same pump, hooked up to a 8 watt vs a 15 watt, the gph of the 15 watt would be so much quicker it would write off the advantage of the longer bulb. I cannot agree with this. It also goes to Carl's point as why the 15 watt Vecton with a longer bulb outperforms a 16 watt...
I'm unsure how you can say a complete manufacturing company is wrong and the things Carl actually tested didn't happen.
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eaf
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Post by eaf on Oct 27, 2015 11:05:22 GMT -5
In all your arguments, you are missing the point that the Vecton 400 out performed the Vecton 300. As well the Pond Advantage 30 watt with a 36" lamp had a bigger difference in sterilization abilities over a 25 Watt A than the 25 Watt Advantage had over the 15 Watt Advantage (both with 18" lamps), even though wattage was closer between the 30 and 25 watt models. If your theories were/are correct, why did the Nektonics bulb style UV that came out in the late 70s which had poor contact time and UVC exposure fail to perform even the most remedial clarification??? As for turnover, in experiments with ponds, this is where I established difference with UV abilities (even with the same UV) between flow patterns and turn over rates. I found better results due to flow patterns that went from one end of the pond to the far side over circulation patterns that had the UV in a loop that was more one sided (even with circulation pumps to move water to the other side). Increasing turnover further improved results. Carl I already tried explaining why Vecton 400 could outperform Vecton 300. Your tests were with cloudy or green water. There water layer thickness becomes important because UV can't penetrate it well, and Vecton 300 runs a thicker water layer. In my case water is clear even w/o sterilizer. I need the sterilizer for sterilization, not clarification, and with clear water UV penetration is way better, so chances are Vecton 300 will outperform Vecton 400 there simply because of running water in a thicker layer and closer to the bulb. Were tests with clear water done? What's Nektonics bulb style?
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Post by Carl on Oct 27, 2015 11:28:29 GMT -5
]Interesting question. Cell regeneration? While in protozoa there is just one cell that when inactivated stays inactivated and can't spawn any more? But good thinking. Interestingly, it's the sunburn analogy that sent me yesterday to look for actual UV water penetration rates. Because from experience, even if you're snorkeling or diving to shallow depth, you still get burned, despite a substantial thickness of water above. My experience has been that when soaking/relaxing in a pool with just my head above water, it is my face that gets burned first. Back to the question at hand. I often do not agree with manufacturers statements of what a UV Sterilizer can do as per gph or aquarium/pond size. I try and stay consistent regardless of whether it agrees or not. Since Devon noted the SunSun Pressurized Pond filter, let me provide one more example; in use of pressurized pond filters (in this case Tetra Models which also make outrageous claims), this one also had a similar rating(about 4000 lph) using a 9 watt lamp. Using their numbers, this was a flow rate of 220 gph per watt, well over anything I would recommend. This unit could not clear the pond. However in adding a 9 watt separate Tetra Compact UV, and running this off from a diverter (so as to slow the flow) in the otherwise same system, the pond cleared. While water turbidity is certainly a factor, it is still a good way to measure results that I was already anecdotally observing. I also provided the example of a 15, 25, & 30 watt advantage, all with the same exact dimensions, the only diference being lamp length, and wattage. Nektonics was major high end aquarium product manufacturer, specializing in marine aquarium products (which at the time were often ahead of their time). Their unique UV Sterilizer fit into UG Filters, HOB filters, etc. and circulated water around a 5 watt UV lamp that was shaped more like a common incandescent lamp. The flow rates were good (or within specs), but the problem here was contact or dwell time. Besides the lack of any clarification abilities, I had multiple Oodinium outbreaks in systems I set up with what at the time cutting edge and innovative UVs. In the end I was wrong as replacement with Aquanetics inline UVs (which were one of the best brands at this time) on these same aquariums cut the incidence of oodinium in half. What would be much more helpful, since you seem to have a lot of time on your hands & I am in desperate need to get back to work that pays my bills and feeds my family; why not figure out a better system to explain the results I have gotten that factors in turbidity, UV design, etc. I will admit that my formulas, that while they have worked well for me over the years, are still quite flawed. What you will not convince me of is that the 1000s of results I have had over the years, both observations and tested are incorrect.
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