Reef nutrition

UV flow rate

Kensington Reefer

Kensington Reefer

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Thoughts, comments

I’ve got 2 57w AquaUV’s
300DT, 40Fuge, 50g in sump
My main purpose is as a bug cyst (ich) zapper
Do I run just 1
Do I run both...parallel or in series
At what flow rate
 
If you were running two, I would think in parallel is better. 600gph running through two in parallel is 300gph each. Less gph means longer dwell time. Longer dwell time means kill more stuff.

If something gets through the first UV at 600gph why would it get killed by the second one?
 
richiev said:
If you were running two, I would think in parallel is better. 600gph running through two in parallel is 300gph each. Less gph means longer dwell time. Longer dwell time means kill more stuff.

If something gets through the first UV at 600gph why would it get killed by the second one?
Click to expand...

I think for turnover rate of water. Unless you planned the plumbing in different input and outputs, there would be some amount using already UV sterilized water if running in parallel. It could be minimal and not be a factor. Plus in parallel would complicate things in terms of plumbing or an additional pump.

600 gph in series should theoretically be close to 300gph in terms of dwell time.
 
richiev said:
If you were running two, I would think in parallel is better. 600gph running through two in parallel is 300gph each. Less gph means longer dwell time. Longer dwell time means kill more stuff.

If something gets through the first UV at 600gph why would it get killed by the second one?
Click to expand...
It’s UV exposure- intensity level (watts) x seconds exposed (inverse of gph). So having them in series means twice the exposure, the equivalent of running half the flow rate (like Randy said). That said, having them in parallel is probably just about as good since on average you’ll be delivering the same increased intensity x exposure to whatever is in the water.

Killing stuff in this case isn’t black and white, it’s probability of killing really. Even the term killing isn’t really what we’re going for, more like enough DNA damage that it can’t replicate. There’s a lot of randomness involved making it more statistical, so really it just boils down to more is better, up to the point of practicality.

Some people who have 2 UV’s plumb them separately, one high flow for algae and bacteria, and the other low flow for parasites. Theoretically it makes sense, but again this isn’t as exact of a science as people want it to be.
 
JVU said:
It’s UV exposure- intensity level (watts) x seconds exposed (inverse of gph). So having them in series means twice the exposure, the equivalent of running half the flow rate (like Randy said). That said, having them in parallel is probably just about as good since on average you’ll be delivering the same increased intensity x exposure to whatever is in the water.

Killing stuff in this case isn’t black and white, it’s probability of killing really. Even the term killing isn’t really what we’re going for, more like enough DNA damage that it can’t replicate. There’s a lot of randomness involved making it more statistical, so really it just boils down to more is better, up to the point of practicality.

Some people who have 2 UV’s plumb them separately, one high flow for algae and bacteria, and the other low flow for parasites. Theoretically it makes sense, but again this isn’t as exact of a science as people want it to be.
Click to expand...
I'm not completely sure that makes sense to me. There's likely some exposure curve to this, but if going slower doesn't matter that much, then generally there'd seem to be no reason to slow down flow either.

Eg taken to the extreme, you might as well run full speed through the UV at max flow rates, because you will turn the water over faster.

100gph on a 100gallon tank in theory being every bit of water gets exposed once an hour. 200gph, each exposure is half as long, but you have twice as many exposures, so the same amount of total exposure.

Serial at 600gph then also being the same as parallel at 300gph, because each unit of water would get the same amount of total exposure.
 
richiev said:
I'm not completely sure that makes sense to me. There's likely some exposure curve to this, but if going slower doesn't matter that much, then generally there'd seem to be no reason to slow down flow either.

Eg taken to the extreme, you might as well run full speed through the UV at max flow rates, because you will turn the water over faster.

100gph on a 100gallon tank in theory being every bit of water gets exposed once an hour. 200gph, each exposure is half as long, but you have twice as many exposures, so the same amount of total exposure.

Serial at 600gph then also being the same as parallel at 300gph, because each unit of water would get the same amount of total exposure.
Click to expand...

Not the same at all. Running in serial essentially makes the two UV units one UV unit with near constant exposure to UV through both UV units.

Cycling water through one UV and then through the entire tank in hopes it will go through the UV again is not the same and would not count toward dwell time.
 
RandyC said:
Not the same at all. Running in serial essentially makes the two UV units one UV unit with near constant exposure to UV through both UV units.

Cycling water through one UV and then through the entire tank in hopes it will go through the UV again is not the same and would not count toward dwell time.
Click to expand...
The 2 UV in series...
There is a “gap” between the 2 units via the connection plumbing (as short as possible)
 
RandyC said:
Not the same at all. Running in serial essentially makes the two UV units one UV unit with near constant exposure to UV through both UV units.

Cycling water through one UV and then through the entire tank in hopes it will go through the UV again is not the same and would not count toward dwell time.
Click to expand...
If you pump water though two in series at 600gph, that's the same amount of dwell time as water going through two in parallel at 300gph.

There's two roads that are 30 miles long running parallel to each other. The speed limit is 30mph. I send a car down each road. The cars will dwell on the roads for 1 hour.

There's a road that is 60miles long, which is made up of two 30 mile long segments. I send a car down it at 60mph. The car will dwell on that road for 1 hour.

Turns out all those cars are convertibles with the tops down. Bald old men are driving, with their partners sunbathing in the back seat. Everyone comes out with an increase in melanomas.
 
Doesn’t UV exposure only kill ich while in the swimming stage?
Id definitely plumb one upstairs Dt to DT to capture free swimmers down low or around the level most of the fish swim with low flow 200-300 gph for the longest exposure making it count. Uv in the sump your only treating the small percentage of swimmers that make it down their and thats not 100% nor is in the DT logistically..Definitely higher percentage of swimmers up top in DT that never make it down the overflow especially in large deep sand bed tanks like yours!! In all the Uv is managing ich not 100% radication as what most articles point out..Two up top at different ends of the tank and levels just ups the percentage where the fish are swimming.. Depending how serious of an outbreak may depend on placements..I do run Uv alot slower then recommend maybe to slow and always feed mixed frozens and heavy on the garlic pellets thankfully never had an ick breakout yet knock knock!!!
Good luck!!
 
richiev said:
If you pump water though two in series at 600gph, that's the same amount of dwell time as water going through two in parallel at 300gph.

There's two roads that are 30 miles long running parallel to each other. The speed limit is 30mph. I send a car down each road. The cars will dwell on the roads for 1 hour.

There's a road that is 60miles long, which is made up of two 30 mile long segments. I send a car down it at 60mph. The car will dwell on that road for 1 hour.

Turns out all those cars are convertibles with the tops down. Bald old men are driving, with their partners sunbathing in the back seat. Everyone comes out with an increase in melanomas.
Click to expand...
Won't two Uv in different locations or parallel with two intakes have a better chance netting more swimmers then two plumbed inline with one intake? My Uv is plumbed after my return pump plus a second Uv stand alone down deep in the DT run as needed. I really don't mind a pump down low on the back wall others might though..
 
richiev said:
I'm not completely sure that makes sense to me. There's likely some exposure curve to this, but if going slower doesn't matter that much, then generally there'd seem to be no reason to slow down flow either.

Eg taken to the extreme, you might as well run full speed through the UV at max flow rates, because you will turn the water over faster.

100gph on a 100gallon tank in theory being every bit of water gets exposed once an hour. 200gph, each exposure is half as long, but you have twice as many exposures, so the same amount of total exposure.

Serial at 600gph then also being the same as parallel at 300gph, because each unit of water would get the same amount of total exposure.
Click to expand...
Taking anything to the logical extreme will make it seem ridiculous.

Of course there’s more nuance than what you read as a guide from BRS or where ever. UV causes DNA breaks. Some breaks are bad for survival or reproduction, some aren’t. Many are in between, they are bad in certain combinations. So the more UV exposure the more likely to get the desired effect. It’s a LD50 (dose that causes 50% to die or be unable to reproduce), or LD75, or whatever. There’s no such thing as LD100, practically speaking. People arbitrarily decide what kill rate is the target, and that’s how they decide what the exposure in amount of UV light per surface area should be. Organisms also can fix the breaks at a certain rate, so you are better off delivering the dose in 1 session or a couple sessions than microdosing, but either can work. The other complication is that UV-C (the one we are talking about) doesn’t penetrate tissue well, so multicellular organisms like parasites need a higher dose to penetrate multiple layers.

The UV sterilizers generally get longer as they get stronger, so having 2 in series is almost exactly the same as 1 larger one of twice the wattage. It doesn’t matter if there’s a little tubing between them. Having them in parallel but both in the same chamber in the sump is very similar (but not exactly the same) since a lot of the water coming through will get the double dose as it does. Taking your extreme example of having very high water flow and having all the water go through the UV every hour could be effective, depending on how quickly different organisms take to fix DNA breaks, but it’s less practical.
 
richiev said:
If you pump water though two in series at 600gph, that's the same amount of dwell time as water going through two in parallel at 300gph.

There's two roads that are 30 miles long running parallel to each other. The speed limit is 30mph. I send a car down each road. The cars will dwell on the roads for 1 hour.

There's a road that is 60miles long, which is made up of two 30 mile long segments. I send a car down it at 60mph. The car will dwell on that road for 1 hour.

Turns out all those cars are convertibles with the tops down. Bald old men are driving, with their partners sunbathing in the back seat. Everyone comes out with an increase in melanomas.
Click to expand...

That's assuming that the cars go on each road and don't take a detour and promise to immediately make a u-turn and go back through one of the two roads before going somewhere else on one of the non-designated roads....
 
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JVU said:
Taking anything to the logical extreme will make it seem ridiculous.

Of course there’s more nuance than what you read as a guide from BRS or where ever. UV causes DNA breaks. Some breaks are bad for survival or reproduction, some aren’t. Many are in between, they are bad in certain combinations. So the more UV exposure the more likely to get the desired effect. It’s a LD50 (dose that causes 50% to die or be unable to reproduce), or LD75, or whatever. There’s no such thing as LD100, practically speaking. People arbitrarily decide what kill rate is the target, and that’s how they decide what the exposure in amount of UV light per surface area should be. Organisms also can fix the breaks at a certain rate, so you are better off delivering the dose in 1 session or a couple sessions than microdosing, but either can work. The other complication is that UV-C (the one we are talking about) doesn’t penetrate tissue well, so multicellular organisms like parasites need a higher dose to penetrate multiple layers.

The UV sterilizers generally get longer as they get stronger, so having 2 in series is almost exactly the same as 1 larger one of twice the wattage. It doesn’t matter if there’s a little tubing between them. Having them in parallel but both in the same chamber in the sump is very similar (but not exactly the same) since a lot of the water coming through will get the double dose as it does. Taking your extreme example of having very high water flow and having all the water go through the UV every hour could be effective, depending on how quickly different organisms take to fix DNA breaks, but it’s less practical.
Click to expand...
Sorry to belabor the point, and ignoring the extreme version I said and instead the one about the roads, if the consideration is maximizing time the stuff is exposed to UV light, the parallel and serial setup are the same then right?

Assuming all other things the same, if the water is flowing through at 300gph, it's going half as fast as 600gph. If it goes through a 1ft UV at half-speed, that's the same dwell time as going through 2x1ft at twice the speed. So it should be the same effect either way.

Going a step further, if what you're doing is splitting a 600gph input into 2-300gph inputs, then it should be the same effect either way how you plumb it up.

Code: 
Pipe setup 1:

          ---------------------
         |   300gph            |
         |   ---------------   |
         |  |              |   |
         |  |              |   |
----------  |              |   ----------
            |              |
600 gph     |              |      600gph
            |              |
----------  |              |   ----------
         |  |              |  |
         |  |              |  |
         |   ---------------  |
         |   300gph           |
          --------------------


Pipe setup 2:

------------------------------
                  
          600 gph 
                  
------------------------------

In both those setups the water takes the same amount of time to get from the left to the right overall, and any bit of water spends the same amount of time under light.

Also note here I'm not saying one is better than the other, but they're the same, as far as I can reason through (or math through).

Thinking of it differently, if I have a tub of 50 gallons of water connected to a 50gph pump, it doesn't matter how many parallel uv sterilizers I stick in there, it'll still take 1hr to empty the tub. If I have 1000 parallel pipes with uv sterilizers on it, you'd still get the same dwell time overall as having 1000 uv sterilizers in serial, because the water in each pipe needs to slow down proportional to the number of pipes.

Maybe chatgpt would be able to explain this better.

Edit: chatgpt link #1 which says go parallel, but I don't know that I believe it's full explanation: https://chatgpt.com/s/t_687fcb569dd88191b85baa2f0e136eb4
I have a deepresearch version running too.
 
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richiev said:
Sorry to belabor the point, and ignoring the extreme version I said and instead the one about the roads, if the consideration is maximizing time the stuff is exposed to UV light, the parallel and serial setup are the same then right?

Assuming all other things the same, if the water is flowing through at 300gph, it's going half as fast as 600gph. If it goes through a 1ft UV at half-speed, that's the same dwell time as going through 2x1ft at twice the speed. So it should be the same effect either way.
Click to expand...
Same exposure for the water going through, yes. But assuming you are saying the setup with 2 UV’s is twice the wattage of the 1 UV setup, the one going through 2 UV’s at twice the rate is treating twice as much water/pests per unit time, and also importantly giving the pests half as much time to repair their DNA before the next round. So, not the same overall effect.

richiev said:
Going a step further, if what you're doing is splitting a 600gph input into 2-300gph inputs, then it should be the same effect either way how you plumb it up.

Code: 
Pipe setup 1:

          ---------------------
         |   300gph            |
         |   ---------------   |
         |  |              |   |
         |  |              |   |
----------  |              |   ----------
            |              |
600 gph     |              |      600gph
            |              |
----------  |              |   ----------
         |  |              |  |
         |  |              |  |
         |   ---------------  |
         |   300gph           |
          --------------------


Pipe setup 2:

------------------------------
                 
          600 gph
                 
------------------------------

In both those setups the water takes the same amount of time to get from the left to the right overall, and any bit of water spends the same amount of time under light.
Click to expand...
Yes. Assuming same UV wattage and length. Although, note that larger UV’s sometimes have a physically larger bore, which increases the average distance from the bulb to the pest and therefore decreases the average dose to the pests as they go through. But assuming the same bore size (not like how you drew it) would be the same.

richiev said:
Thinking of it differently, if I have a tub of 50 gallons of water connected to a 50gph pump, it doesn't matter how many parallel uv sterilizers I stick in there, it'll still take 1hr to empty the tub. If I have 1000 parallel pipes with uv sterilizers on it, you'd still get the same dwell time overall as having 1000 uv sterilizers in serial, because the water in each pipe needs to slow down proportional to the number of pipes.
Click to expand...
When I was talking about in series vs in parallel before I was considering in series would be separate setups- separate pumps, tubing etc. Like 2 completely separate UV systems sitting in the same sump. Your examples are showing them connected to the same pump/tubing system. So we weren’t talking about the same thing.
 
Did some Googling. I didn't do a thorough read, but the headline I got from it is what I suspected. Total UV dosage (power x time) is more important that time or power alone.

uvsolutionsmag.com

UV-C Intensity, Time and Total Dose Germicidal Efficacy » UV Solutions

Arnav Kumar, student, Oxford Academy (then University of California, Santa Barbara) Andrea Peña, student, Savanna High School, Anaheim, California Sigal Willner, student, New York Medical College Arthur Kreitenberg, clinical professor, […]
uvsolutionsmag.com uvsolutionsmag.com

Background
In the 19th century, the Bunsen-Roscoe research team found that the biological effect of light energy is directly related to the total energy or dose delivered, irrespective of how it is administered.5 This means that the biological effect, reduction of microbes in the current discussion, is related fundamentally to the total mJ/cm2 delivered. The lamp power, distance and exposure time are not important, so long as their combination delivers the required UV-C dose
Click to expand...

Discussion
The Bunson-Roscoe law seems to hold true for UV-C’s germicidal effect on Staph at very high intensities. This information is useful as infection control professionals may be assured that whole-room disinfection devices applying UV-C very rapidly at high intensity are at least as effective as devices that apply low-intensity UV-C over long intervals.
Click to expand...
 
One of the best studies and longest Ive read on Cryptocaryon irritans ( marine ich) a while back was by Colorni and Burgess 1997 which was an extremely lengthy phd research paper! I could not find that research paper but this article in the link sources some of their studies as well as other research papers on the subject.
Whats notable is fish can be asymptomatic of marine ich acting like carriers with no symptoms for 6 month or so when a new clean fish is added that one can develop ich immediately . They hatch mostly at night from the sand and rocks while most fish are laying their sleeping so easy prey..They do talk a bit regarding Uv
Anyhow good read enjoy!

edis.ifas.ufl.edu

FA164/FA164: Cryptocaryon irritans Infections (Marine White Spot Disease) in Fish

University of Florida, Institute of Food and Agricultural Sciences Extension outreach is a partnership between state, federal, and county governments to provide scientific knowledge and expertise to the public. The University of Florida (UF), together with Florida A&M University (FAMU)...
edis.ifas.ufl.edu edis.ifas.ufl.edu
 
JVU said:
When I was talking about in series vs in parallel before I was considering in series would be separate setups- separate pumps, tubing etc. Like 2 completely separate UV systems sitting in the same sump. Your examples are showing them connected to the same pump/tubing system. So we weren’t talking about the same thing.
Click to expand...
Not to gotcha you, but if it's two pumps each putting out 300gph or a single 600gph pump going in parallel to two UVs, that's the same no? Both are just different mechanical configurations of the water routing.

RE the sizing and what not, maybe I'm misinterpreting the original post, but I assumed it's two equal sized and the only difference is plumbing configuration. Everything held fixed my vibe being both configurations seen equivalent. As long as you don't do crazy town and do 2-600gph separate pumps versus a single 600gph. That definitely would be worse, because total dwell time is halved.

Said differently, ignoring some details, I'm proposing these seem equivalent (600gph being arbitrary):

1. A serial, setup with 2 UV and a 600gph pump
2. A single 600gph pump connected tee-ed to 2 parallel UVs
3. Two separate 300gph pumps powering 2 separate UVs

I originally thought the double 300gph would be better, but I don't think the math works out that way. Given that I think the answer is "doesn't matter", and whichever is easier to plumb and do maintenance on.
 
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