Microorganism UV Dosage Chart

[kendragon]

I came across this great chart that shows the UV dosage required. Top in the list is algae (22mJ/cm^2). Most UV lights can handle this kind of low dosage. It's the higher dosage that becomes tricky to achieve and size. 50mJ/cm^2 is a good all around dosage. As you can see from the chart some microorganism requires 100-300mJ/cm^2. So know what you're targeting before selecting a unit for your system.

 

[kendragon]

UV Sterilizer Rating

Manufacturers do not present their data the same way and it is difficult to understand.

Fluence (UV Dosage) is measured in J/cm^2.

Often you see UV sizing charts with the unit W/cm^2 (EOL). What is this?

W/cm^2 is irradiance (Intensity) of the light measured at the bulb End of Life. This number varies within the reactor. As one can guess, the highest intensity is on the surface of the quartz sleeve and as you move further away it drops dramatically.

See the below analysis where r = 1.25cm (surface of quartz sleeve) with an intensity of 28.38mW/cm^2 and as you move away it drops.


UV Dosage(J/cm^2 or Ws/cm^2) = Intensity (W/cm^2) x Dwell time (s)


The average fluence rate (intensity) should be used for the calculation of dosage and using the highest intensity is not realistic. It should be noted that the average fluence rate does not change with flow rate. You can increase or decrease flow with no affect to fluence rate. Only dwell time changes.

 

[JK47]

If one does not understand the math (I don't do math with letters) is there harm in overdoing it? I have a 40 watt emperor on a 110 gallon QT. Flow rate 240 GPH as an example

 

[kendragon]

If one does not understand the math (I don't do math with letters) is there harm in overdoing it? I have a 40 watt emperor on a 110 gallon QT. Flow rate 240 GPH as an example

If one does not know how to do math, then go by the manufacturer's data.
Emperor data states a dosage of 180mJ/cm^2 at a flow rate of 157/252 gph. Since you are turn the tank vol approx 2X per hour, you can estimate a resulting dosage of 360mJ/cm^2. Well above any parasite listed above. You can drink that water.
No harm to the fish but high water temp, waste of electricity and cost of replacement bulb should be considered.

 

[JK47]

If one does not know how to do math, then go by the manufacturer's data.
Emperor data states a dosage of 180mJ/cm^2 at a flow rate of 157/252 gph. Since you are turn the tank vol approx 2X per hour, you can estimate a resulting dosage of 360mJ/cm^2. Well above any parasite listed above. You can drink that water.
No harm to the fish but high water temp, waste of electricity and cost of replacement bulb should be considered.

That is how I arrived at the 240 GPH target. That was actually timed via a 1 gallon jug to 14 seconds. I had to tee off and restrict a pump to get to that number but I feel like this will be immediate impact if it becomes needed at any point. I don't intend to leave it on all the time and I don't run UV as part of the daily setup but waned it ready and tested in advance.

The bulb is also brand new. I think people assume their bulb last longer than it does because the light is still "on". Thank you very much for your feedback and posting this.

 

[kendragon]

You must ensure the unit is full of water to maximize efficiency. Inlet and outlet should be pointing up or at least put an elbow on the output to force the unit to overflow. Not having the unit on all the time may allow build up on the quartz sleeve. Care must taken if the unit does not have a wiper.
For this setup, throttling the flow is pointless. If the unit is sized right or oversized in your case, reducing flow does nothing for you.
Yes, bulbs degrade with use and should be changed regularly (12-14 months of continuous uses). Ensure you install the right replacement the bulb. There are many cheap bulbs available but are medium pressure (low intensity). Good UV like Emperor uses low pressure bulb (high intensity).

 

[JK47]

You must ensure the unit is full of water to maximize efficiency. Inlet and outlet should be pointing up or at least put an elbow on the output to force the unit to overflow. Not having the unit on all the time may allow build up on the quartz sleeve. Care must taken if the unit does not have a wiper.
For this setup, throttling the flow is pointless. If the unit is sized right or oversized in your case, reducing flow does nothing for you.
Yes, bulbs degrade with use and should be changed regularly (12-14 months of continuous uses). Ensure you install the right replacement the bulb. There are many cheap bulbs available but are medium pressure (low intensity). Good UV like Emperor uses low pressure bulb (high intensity).

Good feedback. Thanks again for advice.

 

[Drstrangelove]

Great find. Thanks a lot for the information.

 

[cigars]

Ken is a filtration GURU!

 

[kendragon]

Taking Monster Fish Keeping to the Next Level

Redox also known as Redox Potential, oxidation potential, & ORP (oxidation reduction potential) describes the ability for the loss of an electron by a molecule, atom or ion to the gain of an electron by another molecule, atom or ion. Without this ability to gain electrons many minerals cannot be absorbed and properly assimilated during stress or disease.


The use of a true UV Sterilizer impacts Redox Balance in a different way than water changes or additional minerals; the UVC irradiation destroys destructive oxidizers in the water column which can otherwise add oxidative stress to fish. This is done by changing the magnetism of the water, aka magnetically charged water. Simply put, think of a Redox Balance of a magnet with opposite poles, high bio load can have a negative effect on a good Redox while water changes, additional mineralization, UV Sterilization and more can have positive effect on Redox. So for those with high bio load who put a lot in filtration medias and water changes, UV may be a simple and compact solution in the balance game.
It should be noted that with the influx of cheap UV clarifiers advertised as true high dwell time level one UV Sterilizers sold via Amazon, eBay, AquaTop, etc; that these will not help with this aspect of Redox maintenance.