Help me with UV flow calculation for Dinos

[Yodeling]

Recently I’ve read that for Dino’s I need to run my UV between 60,000 -90,000 uws/cm2. If that is the case, can someone verify my calculation?

So my 50w Pentair SMART HO unit is runs 30 mJ/cm2 at 26 GPM (I believe that’s the same as 30,000 uWs/cm2). So to achieve the desired 60k, I would simply divide 60,000 by 30,000 then divide 26 by the result? So that would be 13 GPM or 780 GPH? And that would be my upper limit flow for Dino’s?

Any help appreciated.

 

[Shirak]

How much water in your system? It's also about fast turnover since they reproduce so quickly.

 

[Yodeling]

How much water in your system? It's also about fast turnover since they reproduce so quickly.

200g total. To be clear, I want to run the UV as fast as possible (and still effective at Dino eradication) for that exact reason.

 

[Shirak]

200g total. To be clear, I want to run the UV as fast as possible (and still effective at Dino eradication) for that exact reason.

I think the recommendation is for 5x at least turnover per hour. How are you plumbing into the system? Closed Loop? Off the return?

I don't really understand the calculations either but Pentair states the 50w model can go between 1500-1900 gph and work fine for algae which would include Dinos. I think you have plenty of UV power there to get enough turnover and contact time. As long as you are getting true turnover and not just recirculating the sump water over and over. Hence my question on plumbing it.

 

[Yodeling]

From my research, the general consensus is that UV will be ineffective against Dino’s above certain GPH. So that’s why I’m trying to calculate the maximum I can run.

Btw my up is plumbed from DT to DT using a dedicated pump.

 

[Shirak]

From my research, the general consensus is that UV will be ineffective against Dino’s above certain GPH. So that’s why I’m trying to calculate the maximum I can run.

Btw my up is plumbed from DT to DT using a dedicated pump.

Wouldn't that be dependent on the wattage and size of the UV? I would trust the manufacturer if they indicate the unit can run 1500-1900gph.

I would look into verifying the exposure needed for Dinos. But if it helps the chart I was looking at says 1mj = 1000uw
so 30mj at 26gpm = 1560gph or 30,000uw at 1560gph So if you want 60,000uw then yes half the gph to 780gph.

 

[Shirak]

AquaUV recommends 30,000-45,000 uw so I dunno.. They seem to say their units will handle more flow for algae/dinos than Pentair so I tend to believe Pentair more and be on the cautious side.

 

[chadfish]

I think the recommendation is for 5x at least turnover per hour. How are you plumbing into the system? Closed Loop? Off the return?

I don't really understand the calculations either but Pentair states the 50w model can go between 1500-1900 gph and work fine for algae which would include Dinos. I think you have plenty of UV power there to get enough turnover and contact time. As long as you are getting true turnover and not just recirculating the sump water over and over. Hence my question on plumbing it.

Dinos are not algae, they require much higher flux rates as OP has stated.
OP I haven’t looked at your math but you seem smart. Trust your math skills, double check and you’ll be good.
As far as turnover goes - it may be important but is not as scientific as your approach.

also you might have better success putting it directly into the DT as opposed to the sump.

 

[Shirak]

Dinos are not algae, they require much higher flux rates as OP has stated.
OP I haven’t looked at your math but you seem smart. Trust your math skills, double check and you’ll be good.
As far as turnover goes - it may be important but is not as scientific as your approach.

also you might have better success putting it directly into the DT as opposed to the sump.

Yes I realize they are not algae but from everything I have seen the specifications for algae control are effective for Dinos.

So if anyone can confirm actual numbers required to sterilize Dinos with a UV? I can't seem to find a specific number on the web.

 

[Yodeling]

Yeah I think the problem is that there is no definitive guide to targeting Dino’s anywhere. UV manufacturers have guidelines for killing algae vs Protozoa, but Dino’s do no clearly fall into one of those categories although most people agree that they are probably closer to Protozoa. The other problem is that UV manuafactorers don’t seem to agree on the the required irradiation. For instance Pentair recommendations are 2-3 times more conservative than AquaUV. That’s a huge difference.

The reason I posted the thread is because I’ve been running my Pentair UV according to Pentair’s recommendations (260 GPH in a 200g) for several months, and it’s been ineffective at completely eradicating my Ostreo problem. Yesterday I started thinking that perhaps I am not processing enough water and I was about to buy another sterilizer, but in my research I came across AquaUV charts which are suggesting I can run water through the UV much faster. I realize they are different units, but the irradiation values should be universal.

 

[Shirak]

Yeah I think the problem is that there is no definitive guide to targeting Dino’s anywhere. UV manufacturers have guidelines for killing algae vs Protozoa, but Dino’s do no clearly fall into one of those categories although most people agree that they are probably closer to Protozoa. The other problem is that UV manuafactorers don’t seem to agree on the the required irradiation. For instance Pentair recommendations are 2-3 times more conservative than AquaUV. That’s a huge difference.

The reason I posted the thread is because I’ve been running my Pentair UV according to Pentair’s recommendations (260 GPH in a 200g) for several months, and it’s been ineffective at completely eradicating my Ostreo problem. Yesterday I started thinking that perhaps I am not processing enough water and I was about to buy another sterilizer, but in my research I came across AquaUV charts which are suggesting I can run water through the UV much faster. I realize they are different units, but the irradiation values should be universal.

Maybe try bumping to 800gph? That would give you 4x turnover and 60,000 uw with a 50w UV. From what I have read here on R2R most people that have used the UV run high turnover and fast flow on the UV and the Dino's are gone in a day or two. (for those that enter the water column anyway)

 

[Yodeling]

Maybe try bumping to 800gph? That would give you 4x turnover and 60,000 uw with a 50w UV. From what I have read here on R2R most people that have used the UV run high turnover and fast flow on the UV and the Dino's are gone in a day or two. (for those that enter the water column anyway)

Yeah, actually my precise calculations in the OP suggest 780 GPH is the top range for 60,000 uWs/cm2, but according to my research, Pentair calculates based on lamp end of life, which is 20% lower. So with a new bulb, I could go ~940 GPH. So I'll bump up the flow (somewhere between those two numbers) once the new pump arrives and see what happens. Thanks.

 

[chadfish]

Yeah I think the problem is that there is no definitive guide to targeting Dino’s anywhere. UV manufacturers have guidelines for killing algae vs Protozoa, but Dino’s do no clearly fall into one of those categories although most people agree that they are probably closer to Protozoa. The other problem is that UV manuafactorers don’t seem to agree on the the required irradiation. For instance Pentair recommendations are 2-3 times more conservative than AquaUV. That’s a huge difference.

The reason I posted the thread is because I’ve been running my Pentair UV according to Pentair’s recommendations (260 GPH in a 200g) for several months, and it’s been ineffective at completely eradicating my Ostreo problem. Yesterday I started thinking that perhaps I am not processing enough water and I was about to buy another sterilizer, but in my research I came across AquaUV charts which are suggesting I can run water through the UV much faster. I realize they are different units, but the irradiation values should be universal.

Back when I was researching this exact thing, I was able to find at least one study that specified dinoflagellate UV kill flux

 

[saltyhog]

Don't make it complicated and don't go by manufacturer's recommendations. Dinos can encyst and the numbers on the box don't apply to dinos.

With a 200 gallon display I would run it between 200-600 gph. Middle of the road would be better IMO as your unit is under sized for dinos(again manufacturer's recommendations are not intended for dinos).

 

[Idech]

I used a low GPH (251) and it worked for me. I couldn’t really find anything on the web. Sometimes I read it needed to be high, sometimes low.

I saw a Youtuber setup with the same size tank I had and same sterilizer and went with what he did. And it worked.

 

[Yodeling]

Hi

I used a low GPH (251) and it worked for me. I couldn’t really find anything on the web. Sometimes I read it needed to be high, sometimes low.

I saw a Youtuber setup with the same size tank I had and same sterilizer and went with what he did. And it worked.

How big is your tank? I ran my UV at 260gph on my 200g system for 3 months and it didn’t do much. I cranked it up to 660gph yesterday and it’s starting to work I think. I’m waiting for a new pump to raise it even higher.

 

[Idech]

Hi


How big is your tank? I ran my UV at 260gph on my 200g system for 3 months and it didn’t do much. I cranked it up to 660gph yesterday and it’s starting to work I think. I’m waiting for a new pump to raise it even higher.

Mine is 75 gallons, but probably more like 65 because of sand and rocks.

 

[Yodeling]

So I just wanted to post an update. My remaining Ostreopsis have been completely eliminated in a few short days after bumping up the flow to 3-4x turnover. Prior to this, I was running low flow (1x turnover) for 3 months and it has proven to be completely ineffective.

P.S. At 3-4x turnover, my flux rate was around 60,000 uWs/cm2, while 1x turnover was 180,000 uWs/cm2 (Pentair recommended).

 

[Idech]

Great news !

 

[Karliefish]

So I just wanted to post an update. My remaining Ostreopsis have been completely eliminated in a few short days after bumping up the flow to 3-4x turnover. Prior to this, I was running low flow (1x turnover) for 3 months and it has proven to be completely ineffective.

P.S. At 3-4x turnover, my flux rate was around 60,000 uWs/cm2, while 1x turnover was 180,000 uWs/cm2 (Pentair recommended).

I have a huge Ostreposis outbreak in my 350G tank and I have been running 1x turnover for over 3 months and it has been a complete failure. Reading your post gives me hope that I need to up my turnover. I already have dual UV’s with over 120Watts so I know that isn’t the problem. What were the early indicators you saw in your tank that you knew it was working? Thank you for your post - I now have hope again1