Question: UV Sterilizer Flow Rate

[nickkohrn]

I have a Bashsea media chamber that contains GFO, and the inlet is plumbed from the output of my UV sterilizer because I don’t have the room for a manifold or a separate pump to provide the media chamber with its own water supply.


I have a flow sensor connected to my Apex, which monitors the inlet from the pump to the UV sterilizer. Therefore, it tells me what the flow rate is through my UV sterilizer and media chamber. I have noticed that the flow rate to consistently tumble the GFO is lower than the lowest suggested flow rate for the UV sterilizer. You can see the suggested flow rates for the UV sterilizer in the attached photo.

I employed the UV sterilizer mainly for water clarity; I don’t intend to use it to control, prevent, or eradicate parasites.


The flow rate that allows my GFO to consistently tumble is around 50 gallos per hour (189 liters per hour). I like to feed heavily, and the amount of GFO that keeps my phosphates where I want them is one tablespoon. So, it tumbled violently when compared to a larger amount of GFO with the same flow rate.


With that in mind, do you see anything wrong with having the flow rate through my UV sterilizer be less than the lowest suggested flow rate?

Thank you!

 

[Hermie]

The size of your total water volume comes into play when lowering the flow rate through UV.
Basically it probably won't be detrimental.

• organisms moving through your UV will more likely die
• fewer organisms per hour will move through your UV

So, the flow rates recommended by the manufacturer are for a 130 gallon system, what size is yours? if it's smaller than 120 gallons then one could "say" that you are still within their flow specs being that their maximum flow rates are for a system higher than yours.

 

[nickkohrn]

The size of your total water volume comes into play when lowering the flow rate through UV.
Basically it probably won't be detrimental.

• organisms moving through your UV will more likely die
• fewer organisms per hour will move through your UV

So, the flow rates recommended by the manufacturer are for a 130 gallon system, what size is yours? if it's smaller than 120 gallons then one could "say" that you are still within their flow specs being that their maximum flow rates are for a system higher than yours.

I have a Waterbox 100.3, which is roughly 97 gallons before displacement. So, I probably have 85-90 gallons of total water volume in my system.

 

[Hermie]

I have a Waterbox 100.3, which is roughly 97 gallons before displacement. So, I probably have 85-90 gallons of total water volume in my system.

so roughly 77% of 130 gallons (my math) which maps to a Suggested flow of 60 GPH (77% of 79GPH). I'd say that's your ideal number (60GPH) so it's just up to you what you want to prioritize.
50GPH is 80% of the suggested flow, which according to my guesstimation is entirely serviceable to achieve UV results. If the UV is causing issues from "over sterilizing" (if that's possible) you can always set it on a timer.

 

[nickkohrn]

so roughly 77% of 130 gallons (my math) which maps to a Suggested flow of 60 GPH (77% of 79GPH). I'd say that's your ideal number (60GPH) so it's just up to you what you want to prioritize.
50GPH is 80% of the suggested flow, which according to my guesstimation is entirely serviceable to achieve UV results. If the UV is causing issues from "over sterilizing" (if that's possible) you can always set it on a timer.

Thank you for your help! It was insightful and what I was hoping for.

 

[Firemanreefkeeper]

I have that same UV sterilizer and my flow rate is 60gph. I measured it today doing a WC. The slower the flow, the more contact time the water has with the light, thus a better sterilization rate. I think I read somewhere the minimum flow is 40 gph. for the 25watt unit.