57w uv sterilizer in 90gallon flow rate help?

[Warpigdave]

I have 57w uv sterilizer on my 90g. What’s a good flow rate for killing parasites? I’m currently running it at about 1000gph because according to aqua uv 1066gph is 90,000 (whatever units). But that just seemed high to me.

 

[KrisReef]

Interesting rate and exposure problem.

The slower the water passes through the UV the more deadly the kill rate. Too slow wastes killing exposure and too fast allows survival of the desired massacre.

That combined with the tank size of 90 gallons, is 10 times tank size (900 gph) going to kill everything in the water more efficiently than 5 times/hour with heightened sterilization at the slower speed?

The answer should come with the recommendations provided with the unit for gph to eliminate parasites in marine waters. Running it a little slower than maximum is where I would aim with that over-sized sterilizer, but the mfgr may have considered that when they made their recommendations, just to keep it killing reasonably well for hobbyists who are not careful to understand how the product works?

Not much of an answer since I don’t know the product specifications but I hope it helps you feel confident about the gph you select.

 

[MrWellington]

My understanding is "dwell time" of water going through the UV chamber determines whether it's targeting parasites vs. bacteria/viruses. With two return pumps, I have one side set to ~500 GPH across a 55W UV.

UV doesn't "kill" as much as it sterilizes. i.e. limiting a single-cell organism's ability to reproduce.

 

[rsp919]

I'm setting up a 92 gallon with a 57 watt uv. My original plan was to run 2 separate uv's. One for algae and one for parasites. Then came along BRS recommending to oversize and just run one. After hours of videos and reading I has having the same issue, what flow rate to do both on the oversized uv??? Finally said screw it and called BRS. They recommended between 400 gph. Hoping to run into Ryan(BRS) at Reefapolooza this weekend and see if he can confirm that rate. Will report back.

 

[Warpigdave]

So the recommended is 1066 GPH but everyone here is saying lower. Now I’m confused.

 

[rsp919]

So the recommended is 1066 GPH but everyone here is saying lower. Now I’m confused.

That 1066gph is for a 57 watt uv on a 355 gallon tank. Over 10x turnover is way to much. the parasites would be blasted through so fast the uv doesn't have time to sterilize them.

 

[The_Paradox]

My understanding is "dwell time" of water going through the UV chamber determines whether it's targeting parasites vs. bacteria/viruses. With two return pumps, I have one side set to ~500 GPH across a 55W UV.

UV doesn't "kill" as much as it sterilizes. i.e. limiting a single-cell organism's ability to reproduce.

Dwell does not matter, what matters is total dose.

 

[rsp919]

For a 90 gal you can use a 25 watt. If you already have the 57w I would shoot for 4x turnover. That should take care of parasite and algae.

 

[piranhaman00]

It’s remarkable all the continued misinformation about UV and the “facts” people post.

 

[Warpigdave]

So 1066gph or 600gph only matters for tank size? Isn’t the dwell time affected by those flow rates? If I were running it at 600 GPH then isn’t that dwell time greater than 1066? So what we’re looking at with GPH is more turnover rate?

 

[BetteMidler]

T

So the recommended is 1066 GPH but everyone here is saying lower. Now I’m confused.

The 1066gph is the minimum recommended flow rate for tanks up to 355g. Since you are using it on a 90g & bought a higher watt unit, that changes things. A flow rate of 360gph would be 4x turnover on your tank if in fact you have exactly a 90g volume with sump, etc.. You maximum flow would be closer to the 1066gph minimum rating for this higher wattage UV. I would suggest running it anywhere between 400-1000gph would suffice & a 400-500 range would ideally target both protozoa & algae. I would even say running it up to 1000gph would be sufficient to target both to success on your sized tank.

 

[GT3000XX]

I talked to aquauv a few months ago and they said that the minimum rate is the slowest rate recommended to protect the unit from overheating.

 

[Warpigdave]

So 1066 GPH recommended is for a 355 gallon tank. For a 90gallon it would be 400-500Gph. But I'm confused because 1066gph would only effect turnover rate on both size tanks. It wouldn't change dwell time of the water in the sterilizer. So is turnover rate more important than dwell time?

 

[The_Paradox]

So 1066 GPH recommended is for a 355 gallon tank. For a 90gallon it would be 400-500Gph. But I'm confused because 1066gph would only effect turnover rate on both size tanks. It wouldn't change dwell time of the water in the sterilizer. So is turnover rate more important than dwell time?

Total dose. Dwell only limits a true open loop system.

 

[BetteMidler]

The 1066gph will only target protozoa in a much larger system. For your tank, that flow rate would most likely target both protozoa & algae at 1066gph. That is the whole point, buy a larger wattage UV than recommended to cover both. In reality, two 15w units running at two different flow rates would do the job you are seeking to do with one.

Something that was pointed out. If you use this large of wattage at a lower flow than the vendor guidelines, you are at risk of overheating.

The 400-500 gph range would be the minimum recommended flow and delivery the highest dose to treat both based on your tank size. Any lower, you don't have the turnover.

If you can, get closer to the 1000gph flow to deter overheating of the unit.

 

[Warpigdave]

The 1066gph will only target protozoa in a much larger system. For your tank, that flow rate would most likely target both protozoa & algae at 1066gph. That is the whole point, buy a larger wattage UV than recommended to cover both. In reality, two 15w units running at two different flow rates would do the job you are seeking to do with one.

Something that was pointed out. If you use this large of wattage at a lower flow than the vendor guidelines, you are at risk of overheating.

The 400-500 gph range would be the minimum recommended flow and delivery the highest dose to treat both based on your tank size. Any lower, you don't have the turnover.

If you can, get closer to the 1000gph flow to deter overheating of the unit.

I can get to 1066. That’s what i want to do is kill protozoan and algae. The whole point of me buying a 57w was so that I could have a higher flow rate through it. But people are saying that it should be 400 to 500. So then if I were to get a 25 W would i only run it at 200 GPH? Like I said, I bought the 57w so I can run higher flow. But I’m confused by the chart because of chart lists it for 355 gallon. And it just doesn’t make sense to me because the 1066 gph shouldn’t matter what size gallon of a tank you have, unless they are counting turnover volume and not dwell time. At 1066gph no matter what size the tank the water still gets pushed through at the same speed.

 

[Warpigdave]

I talk to the people at aquauv and they said to run the 57w at 1066. Minimum. He asked why I bought the 57w and not the 25 W.? Which I replied because I wanted to higher flow rate. And he seemed to think that was OK then.

 

[Mikeltee]

How are you calculating flow? I have a 1500gph pump with a flowmeter on it. At 100% I get 450gph. When I plumb the UV in the loop, I get 350gph. I run my UV at 300gph for a 130g display. This is what Aqua Untrviolet recommends. If you are actually pushing 1000gph, you aren't doing anything with the UV.

 

[The_Paradox]

How are you calculating flow? I have a 1500gph pump with a flowmeter on it. At 100% I get 450gph. When I plumb the UV in the loop, I get 350gph. I run my UV at 300gph for a 130g display. This is what Aqua Untrviolet recommends. If you are actually pushing 1000gph, you aren't doing anything with the UV.

Agreed. I see a lot of 1500lpm pumps listed as 1500gph.

 

[Warpigdave]

Its a vectra s2. 1400GPH at zero. My uv sterilizer is directly above it about 6 inches. So I just figured that would be about 1300gph