With Flow meter installed, UV flow rate is lower than I thought

[14 foot reef]

I run an Aqua Ultraviolet SL-200 UV Sterilizer on my 850 gallon reef. The flow recommendations for parasitic kill rate is the following from Aqua Ultraviolet website......
at 90,000 µw/cm2 (EOL) GPH: 3,066

I'm running at 1670 GPH is this flow rate too low and what would the negative effects be. Not worried about heat because I run a 2hp Tradewinds chiller.

The Pentair 200 watt UV Chart says to run 2200 for the same kill rate.

What are the downsides of running this much slower through the UV

?

 

[Quietman]

You won't be as protected against pathogens. I don't think it's a 'hit this number' or it does nothing though. I suspect (as you can tell, this isn't hard data) that you'll have some protection. Also, some pathogens need 180K uw/cm2 or more to be 100% effective. Different designs have different exposures based on how the flow through is designed and which bulb is used so nothing unusual in having different manufacturers with different numbers. The impact on organisms is based on exposure of course so that's relatively (depending on organism) the same.

You can always adjust flow (output valve on pump or dc pump) if you see marine ich or velvet outbreak for example to get a lower flow rate. Also when you add new fish might not be bad idea. If you have algae/dino crank up flow to max (8x tank volume to be really effective on dino but hard to achieve on big tanks). That's what I think is really useful with the flow meter - you can adjust for specific exposures when using UV.

 

[14 foot reef]

You won't be as protected against pathogens.... ??????

Most flow charts have me well beyond the flowrate, I was worried about overkill, not underkill..

 

[blaxsun]

You won't be as protected against pathogens.... ??????

Most flow charts have me well beyond the flowrate, I was worried about overkill, not underkill..

It's two-fold. I think what he means is that you won't cycle your entire tank as many times in an hour with a slower flow rate - which means you won't be exposing the optimal level of pathogens in the water. On the flip side, anything going through your UV is effectively getting a double dose so it is theoretically dead (not just sterilized).

The flow rate for my AquaUV on my 200-gallon system is around 650Gph, or about 3-3.25x turnover. By comparison you're getting about 1.85-2x turnover on yours. So yes, if you can boost your flow rate to between 2,500-3,000Gph you will probably see more of a benefit based on the size of your tank. Hopefully that helps.

 

[14 foot reef]

It's two-fold. I think what he means is that you won't cycle your entire tank as many times in an hour with a slower flow rate - which means you won't be exposing the optimal level of pathogens in the water. On the flip side, anything going through your UV is effectively getting a double dose so it is theoretically dead (not just sterilized).

The flow rate for my AquaUV on my 200-gallon system is around 650Gph, or about 3-3.25x turnover. By comparison you're getting about 1.85-2x turnover on yours. So yes, if you can boost your flow rate to between 2,500-3,000Gph you will probably see more of a benefit based on the size of your tank. Hopefully that helps.

Perfect help, thank you. Problem is pump is at max flow, so this is what it is, its an AC pump and traveling 50' horizontal and 8 feet vertical.

 

[blaxsun]

Perfect help, thank you. Problem is pump is at max flow, so this is what it is, its an AC pump and traveling 50' horizontal and 8 feet vertical.

Before spec'ing out my UV I found an article that indicated anything above a 1.5x turnover rate for a UV was sufficient. More is always better of course, but based on the 60' length I'd wager you're probably doing pretty good.