Proper UV Flow?

[edkhutch]

Hey all,
looking for some advise on a UV flow. Everywhere I look I find another answer so i figured i would turn to the experts.

57 watt AQUA UV on 300 gallons.

parasite flow rate =
Alge kill flow rate =

[Member No. 1]

From AquaUV site.

https://aquaultraviolet.com/wp-conte...-Water-Web.pdf

[edkhutch]

Yes that is what came with the UV but if i am understanding it correctly it says:
Reef Tanks -A UV rated in the 30,000-45,000 columns is ideal for the reef environment .UV’s rated
at higher kill rates will destroy the planktonic food supply for the reef.
to achieve this i need a flow of 3200 - 2133 how can that flow rate be achieved with 3/4 fittings? i have a 6500gph hammerhead on a 1.5 manifold and the best i can get is 690-700 gph.

[Spaced Cowboy]

Huh. The table I use is the one from my UV filter manual (an Emperor Aquatics smart-HO 50W system). Two things strike me about the above AquaUV table.

• The flow rate only goes up to 90 uWs/cm^2, whereas the EA system lists 180 uWs/cm^2 as what you need to sterilize protozoa like ich.
• My manual lists both a maximum and recommended flow rate for whichever level of sterilization you want to see. Maximum is new-bulb, recommended is old-bulb.

I don’t know if the aquaUV one is the equivalent of the recommended or maximum output value, but my innate cynicism for manufacturer figures leads me to believe it’ll show up as whatever sells best.

As a data-point, on my system, the ich-rate is 260/330 gph (@180 uWs/cm^2) and I run it at 4 gpm on the meter. YMMV.

[edit: the aquaUV figures given appear to be end-of-life for the UV lamp, having read the blurb at the bottom]

[edkhutch]

RIGHT!! its very odd wording and is open to errors. So i get that all the brands will be different and that makes sense as different body styles will have shorter or longer contact times. but the flow rates for the EA system are more on point or realistic.

[Spaced Cowboy]

Originally Posted by edkhutch

RIGHT!! its very odd wording and is open to errors. So i get that all the brands will be different and that makes sense as different body styles will have shorter or longer contact times. but the flow rates for the EA system are more on point or realistic.

Well, if yours is the twist57 variety, then you could presumably halve their flow-rate for the 90k rate to get the 180k rate. Looking at the 45:90 and 30:60 ratio, it does seem to be a linear relationship.

In your case, for ich that would come to 533 GPH or ~8 gallons per minute, about 2x the rate of mine. Allegedly

For algae/bacteria, it'd be ~50gpm, again about 2x mine.

[edit]
I see you're trying to run it at the fast speed - I don't, I run it at the 'ich' speed - and it could be that trying to get that high level of flow through a twisty-turny filter path just isn't really an option.

I had the opposite problem of slowing down the flow on my Reeflo dart gold, and ball valves were the solution. I'm not sure how you'd increase the flow if a hammerhead can't do it...
[/edit]

[edkhutch]

that moment your math teacher told you about.

[Member No. 1]

Originally Posted by edkhutch

Yes that is what came with the UV but if i am understanding it correctly it says:
Reef Tanks -A UV rated in the 30,000-45,000 columns is ideal for the reef environment .UV’s rated
at higher kill rates will destroy the planktonic food supply for the reef.
to achieve this i need a flow of 3200 - 2133 how can that flow rate be achieved with 3/4 fittings? i have a 6500gph hammerhead on a 1.5 manifold and the best i can get is 690-700 gph.

The slower the flow, the higher the kill rate. I run my 25 on a 120 at 600gph.
You'd be fine running 1,600gph thru it.

[edkhutch]

So if the most i can get out of my pump right now is 600 gph thats still not enough for 300+ gallons. on a 57 watt

[Member No. 1]

Originally Posted by edkhutch

So if the most i can get out of my pump right now is 600 gph thats still not enough for 300+ gallons. on a 57 watt

At that low of a flow rate you will be well over 90,000 µw/cm² You need to be in the 30,000-45,000 µw/cm² if you are keeping a reef tank.

I think the UV is sized correctly for your tank, but you need to address the low flow from your pump.

Have you verified it's flow rate? If so how?

[edkhutch]

I have a 1'' Apex Flow meter on it. i am keeping a mixed reef mostly lps. i have it at about 550 gph at the moment for pest control.

[EnderG60]

I used on on my old 300, if you want it to kill ich the flow rate is 150 GPH.

I ended up getting a second 57w to at least turn the tank over once an hour, then moved to a 150w for the new tank.

EDIT: if you just want algea control put it inline with your main return. If you want to kill EVERYTHING, dont have it on your main return because it will kill all the "good critters" on the way up from the sump.

[clevername]

read other manufactures rates. I have the same one, run at 300GPH. If you go higher you wont kill parasites and its completely useless. Do the research

[clevername]

Originally Posted by EnderG60

I used on on my old 300, if you want it to kill ich the flow rate is 150 GPH.

I ended up getting a second 57w to at least turn the tank over once an hour, then moved to a 150w for the new tank.

EDIT: if you just want algea control put it inline with your main return. If you want to kill EVERYTHING, dont have it on your main return because it will kill all the "good critters" on the way up from the sump.

What one did you end up getting. Im thinking about upgrading just like yourself

[EnderG60]

Originally Posted by clevername

What one did you end up getting. Im thinking about upgrading just like yourself

I picked up a used Emperor HO 150 Watt UV in need of repair on the cheap.

I also converted an old 40w UV to an 80 by swapping the bulb and ballast, which isnt a bad option.

EDIT: almost forgot, the flow rates are basically based on (how much radiation the bulb puts out) / (how fast the water goes past it) = what it kills.

So remember if you get a nice UV and buy a cheap replacement bulb you have ZERO clue what the flow rate should be because no one tests aftermarket UV bulbs.