UV off return like tee

[QuinnLee512]

Would there be any issue if I cut out the section in red and plumbed in a UV? I will have a gate valve and flow sensor to slow the flow to the UV. This is a dual nozzle return line so the flow out of each nozzle wouldn't be the same. I have a cor20 pump.

 

[TARHEEL78]

I have mine set up similar with no issues.

 

[QuinnLee512]

Oh awesome. That's what I will do then. Any chance you have a manifold off the other side? Debating if I will do that or not.

 

[TARHEEL78]

I do not, sorry I'm no help there.

 

[QuinnLee512]

I have mine set up similar with no issues.

With the return cut, how do you keep it stable? I'm planning on using flexible hose from the UV to the return.

 

[Bartanto]

That barb unscrews to a 3/4” female thread adapter (at least it did on my 525). Do you have room to plumb the UV to that? You’d be treating 100% of the return that way or you could just run to the barb. Wouldn’t help with manifold though…and don’t know what rtn flow you’re looking for.

 

[QuinnLee512]

That barb unscrews to a 3/4” female thread adapter (at least it did on my 525). Do you have room to plumb the UV to that? You’d be treating 100% of the return that way or you could just run to the barb. Wouldn’t help with manifold though…and don’t know what rtn flow you’re looking for

I guess I need to find out what the recommended flow for a 350 and 25w UV are.

 

[dank.reefer]

This is a bit of a crappy drawing but, if you put a ball valve in after the inlet to the uv you can control how much water flows through the uv by opening and closing the valve and you would hve even flow out of both returns. You can route the uv to bypass the ball valve in any configuration you wish. Then by adjusting the restriction(ball valve) in the return line you can adjust the flow through the UV. Running it this way the flow through the return jets should never change.

 

[QuinnLee512]

Does anyone know what the top number in this chart means? I have the 25w classic UV. Trying to determine what the flow into the UV should be.

 

[dank.reefer]

Those are microwatt per square centimeter

 

[QuinnLee512]

Those are microwatt per square centimeter

Is that some sort of rating of the UV? I thought the only number I needed to know was Watts. I got this UV. Trying to figure out what flow rate I should have going through it.

25 Watt Classic UV Sterilizer - Black Body

Aqua Ultraviolet UV Sterilizers will eradicate algae, bacteria, and protozoa without any harmful chemicals or additives! UV lamps emit a wavelength that will alter and disrupt the DNA or RNA of single-celled organisms. Combining the UV lamp into a large housing allows for maximum contact time...

www.bulkreefsupply.com

 

[dank.reefer]

What size tank?

 

[dank.reefer]

What are your goals water clarity or parasite control?

 

[QuinnLee512]

What are your goals water clarity or parasite control?

Is there a both answer? :⁠-⁠) 90 gallons total.

 

[dank.reefer]

It kinda doesn't quite work that way. One flow is too fast to kill parasites and just right for killing enough algea and bacteria to make a difference, and the other flow rate is too slow to move enough water volume through to have any effect on bacteria or algea. So to kill parasites you would be looking at around 150g per hour, to kill algea and bacteria you would be looking between 400-500g per hour. As you can see with the suggested flow rates being so vastly different it would not be very effective to meet in the middle. Instead meeting in the middle would just prove lack luster in either direction. I think what most people do is set it up to protect against parasites and if they have an algea bloom speed up the flow to correct it. If you set the UV up using the method I showed in the drawng it should give you the ability to tweak it just right for your needs and since you are using a flow meter you should really be able to get it dialed in.

 

[TARHEEL78]

With the return cut, how do you keep it stable? I'm planning on using flexible hose from the UV to the return.

I didn't have factory plumbing for my tank. I plumbed it like that from the beginning.

 

[QuinnLee512]

It kinda doesn't quite work that way. One flow is too fast to kill parasites and just right for killing enough algea and bacteria to make a difference, and the other flow rate is too slow to move enough water volume through to have any effect on bacteria or algea. So to kill parasites you would be looking at around 150g per hour, to kill algea and bacteria you would be looking between 400-500g per hour. As you can see with the suggested flow rates being so vastly different it would not be very effective to meet in the middle. Instead meeting in the middle would just prove lack luster in either direction. I think what most people do is set it up to protect against parasites and if they have an algea bloom speed up the flow to correct it. If you set the UV up using the method I showed in the drawng it should give you the ability to tweak it just right for your needs and since you are using a flow meter you should really be able to get it dialed in.

Thanks for this explanation. I'm a little confused by your drawing. My plan was to have a spears gate valve and flow meter on the side that the UV is on. That way I can dial down the flow to 400 on the UV but keep it 800 on the other side.

 

[QuinnLee512]

Or can I just make this simple and have 400gph into the DT and just have a bunch of powerheads? I already have 2 Nero 5s, reefwave 45 and mp40.

 

[threebuoys]

I would place the UV prior to the split to two returns as illustrated in post 6 above.

I believe you can fight both disease and algae simultaneously by using the strongest UV you can afford. I know many disagree with this. If you are interested, I've linked some information that helped me reach my theory.

I think flow rate is not an issue...... See these threads

've seen those videos and i've read quite a few reviews as I'm sure you have. I don't think the "science" is accurate. I would love to see some documentation that describe exactly how the tests that determined that different flow rates were proven. All I've seen has been based on open systems such as those in municipal or industrial water plants.

Below are comments I've posted elsewhere. I certainly don't have scientific proof for my theory either, but anecdotally, I've been very satisfied with my experience. Sorry to be long winded below, and in any case, UV sterlization is definitely beneficial


"My thoughts FWIW.....keep it simple and cheap, don't over engineer to fix what's probably inconsequential issues.

Plumb it directly in the return line to the tank. No need to buy a second pump or add additional plumbing.

Run UV full time, why wait until a problem occurs?

Run at whatever flow rate you desire for the return to tank, don't worry about altering the speed to accommodate the UV.

I have read the various opinions/recommendations about flow. Some say it depends on what problem you are trying to solve. For example, the reproduction rate of certain bacteria that causes cloudiness in the water column is to double every 20 minutes or less. In that case, the higher flow rate will more than keep up with the bacteria population explosion and aid in water clarity.

Some feel that a slower rate will be more effective in fighting parasites. Likewise, algae in the water column can be tackled by UV, and since it reproduces more slowly, why use a fast flow rate.

In either case, the UV alters the DNA of single cell life to prevent reproduction.

I view it a bit like exposure to the sun's UV rays. If every 5 minutes of sun I get is followed by 5 minutes of shade, I'm still gonna get sunburned if I'm exposed too long. Likewise for the bacteria. If I have a flow rate of say 5 to 10 times tank volume per hour, then the parasites I'm trying to target are still getting exposed to 6 to 12 minutes of UV every hour while the bacteria with the rapid reproduction rate are still getting exposure before they are able to double in population in 20 minutes.

I can turn off the power to the sterilizer if I get concerned that I'm using too much UV (to extend bulb life perhaps), but so far that's not a problem. I can also plug it into a receptacle/switch shared with the return pump to make sure it is turned off anytime no water flow.

A lot of room for different opinions based on individual experience. In any case, I recommend the use of a UV sterilizer and look for the cheapest you can buy. Again, they are really very simple and most of the products on the market, high or low priced, use the same replacement bulbs.

"If you are able to find documented flow rates, as opposed to suggested flow rates by vendors (of which I have seen many), I would also like to see it. All I've been able to find with reasonable documentation are flow rates in municipal water treatment plants. Of course that is a much different environment. Not only is the scale of operation in a much bigger universe, but a major difference is the water treatment plants are not closed systems as our aquariums are. Hence, my recommendation for rapid turnover. Water treatment plants keep each ounce of water in continuous exposure for a longer period of time which destroys all pests before the water is distributed to their customers. We on the other hand return the water into a closed system where it can be immediately reinfected by what is there. Some of the bad bacteria we fight to remove from the water column (often those repsonsible for bacteria blooms) have a documented reproductive doubling rate of less than 20 minutes. So, the best way to fight that is to have a cycle that flows 100 percent of the water in less than 20 minutes. Other pests, larger than 1 cell may require longer exposure which in a closed system is accomplished by repeated passes in the smaller UV devices we have available rather than one that might be multiple meters long. I wish I could offer a scientific study to validate what I'm saying, but I haven't found it yet. My logic may be flawed, but I believe the 5 - 10 water turnovers an hour in a closed system is the best way to match what happens in industrial water plants. And so far, I have been very pleased with my experience which as I've pointed out is anecdotal at best."

To support my theory another bit of information from

Germicidal UV Dose UV Irradiation Dosage Table​

Germicidal UV dose table shows the UV dose needed to inactivate germs
www.americanairandwater.com
quote:

"Please note that many variables (air flow, humidity, distance of microorganism to the UV light, irradiation time) take place in a real world environment that make actual calculating of the UV dosage very difficult. However, it is proven that UV light will kill any DNA-based microorganism given enough UV dosage. UV breaks down DNA on a cumulative basis. Therefore, as air circulates through the ductwork of an HVAC system containing an UV light, the UV light continuously disinfects the air. If a microorganism is not effectively deactivated on the first pass through the ductwork, the UV light will continue to break its DNA down on subsequent passes. Microorganisms do not sit in a static environment in HVAC systems except on coils which can be exposed to UV light also. Microorganisms multiply rapidly if not controlled. The UV light helps to reduce airborne microorganisms from the indoor environment."

 

[QuinnLee512]

I would place the UV prior to the split to two returns as illustrated in post 6 above.

I believe you can fight both disease and algae simultaneously by using the strongest UV you can afford. I know many disagree with this. If you are interested, I've linked some information that helped me reach my theory.

I would like to keep it simple like post 6. My concern is whether 400gph into the DT is enough to achieve the recommended turnover.