undermind said:
What made you scale up the GPH from your original plan? Is it that you'd like more turnover?
I'm close to pulling the trigger on the same unit. And I'm at about the same water volume (100g).
I'm a little thrown off by the manufacturer flow rate for algae though. 2100gph seems pretty high compared to the 943gph suggested rating by Pentair for their 40w Smart UV. Lifegard rates their 55w for up to 350g aquariums. But I'm not sure whether you can lower the 2100gph based on tank size. For example, is 30,000 μW/cm2 of UVC at 2100gph on a 350g tank equivalent to 598gph on a 100g tank? That's just reducing both gph and tank size by 28 percent - the difference between tank sizes.
I'm thinking that the gph rating at 30,000 μW/cm2 doesn't change regardless of tank size though, is that correct?
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I believe there is a max flow rate that my sump and weir can handle without being too loud. I’ve run it at 500 and had no problem. I really don’t want to get much higher than 6-800 due to that. I’m confident I will get sufficient dosage at that flow rate.
As for the math, I believe the uvc dosage (uW/s) is tied to gph but not system volume. Diameter of the uv system, high output (amalgam) bulb, etc all play into that dosage and increase contact time. I think the system volume they give is more of a suggested gph for a given system volume. So turn over does matter, but doesn’t directly change that dosage number.
I think the decision process is: chose your desired turn over rate 5-6x or say 10x if you are doing triton. That gives you your gph. Then chose your uv wattage (and things like bulb type, diameter etc) to get the required dosage you want. Lastly make sure the form factor of what you chose will fit. I regret getting the 5” diameter but I think I needed to as I didn’t have much length for 55”.
In summary,6-800 gph will give me 6-8x turnover and will give a high enough dosage to probably kill ich. Not a perfect calculation but feels right. Could probably do okay with one size down too. I oversized I think.
I believe there is a max flow rate that my sump and weir can handle without being too loud. I’ve run it at 500 and had no problem. I really don’t want to get much higher than 6-800 due to that. I’m confident I will get sufficient dosage at that flow rate.As for the math, I believe the uvc dosage (uW/s) is tied to gph but not system volume. Diameter of the uv system, high output (amalgam) bulb, etc all play into that dosage and increase contact time. I think the system volume they give is more of a suggested gph for a given system volume. So turn over does matter, but doesn’t directly change that dosage number.I think the decision process is: chose your desired turn over rate 5-6x or say 10x if you are doing triton. That gives you your gph. Then chose your uv wattage (and things like bulb type, diameter etc) to get the required dosage you want. Lastly make sure the form factor of what you chose will fit. I regret getting the 5” diameter but I think I needed to as I didn’t have much length for 55”.In summary,6-800 gph will give me 6-8x turnover and will give a high enough dosage to probably kill ich. Not a perfect calculation but feels right. Could probably do okay with one size down too. I oversized I think.