Pentair UV Killing Flow

[ca1ore]

I appreciate the comments, but how do I explain that when the UV Pump and Sterilizer are off, temperature is stable. As soon as i turn it on, it begins to rise?

Simple, because you’ve just added 145 watts of additional heating ...... 40 from the UV and 105 from the sicce pump.

 

[JPK_Esquire]

Simple, because you’ve just added 145 watts of additional heating ...... 40 from the UV and 105 from the sicce pump.

So maybe take the Sicce pump out of the sump and run it externally inline with the UV? Would that help?

 

[Drewbacca]

Are we SURE that the manufacturers suggested flow rating for these uv's isnt just for what is going IN to the Sterilizer? maybe Not meant to tested for after? Just wondering. Installing my first one...a pentair 40 watt with a 1900 dc pump. so glad i read all this because what i thought was overkill might be just enough now.

 

[JPK_Esquire]

Are we SURE that the manufacturers suggested flow rating for these uv's isnt just for what is going IN to the Sterilizer? maybe Not meant to tested for after? Just wondering. Installing my first one...a pentair 40 watt with a 1900 dc pump. so glad i read all this because what i thought was overkill might be just enough now.

If you still plumbing, I would try to do the following: (1) run the UV vertical if possible (many of the comments I've read on UV sterilizers suggest running vertically as you get more time in the UV--wasn't possible for mine because my wife did not want the UV outside of the cabinet underneath the tank), (2) run the pump externally inline in a closed loop with the display if possible. I think that is what I am eventually going to do. Get a new DC pump and run it externally with hard PVC coming out of the display tank at the top, dropping down the back and into the external pump, through the UV, and then back up to an outlet on the other side of the overflow. Good luck. Please post if you have similar flow or heat issues.

 

[Drewbacca]

If you still plumbing, I would try to do the following: (1) run the UV vertical if possible (many of the comments I've read on UV sterilizers suggest running vertically as you get more time in the UV--wasn't possible for mine because my wife did not want the UV outside of the cabinet underneath the tank), (2) run the pump externally inline in a closed loop with the display if possible. I think that is what I am eventually going to do. Get a new DC pump and run it externally with hard PVC coming out of the display tank at the top, dropping down the back and into the external pump, through the UV, and then back up to an outlet on the other side of the overflow. Good luck. Please post if you have similar flow or heat issues.

Thanks for the advise, I did mount it vertical. Unfortunately I plumbed it out from the return right back into the return as I couldnt think of another way at the moment. Since its Identical to my return pump and have identical desired flow rates (950gph for algae uv & a out 1000 for 10x turnover on my refugium based system) and since the OUTput plumbing on the UV runs inches away from my teturn plumbing going up to the Display, I think I'm just going to plumb my UV output to run up as my return. Perhaps with a valve or two where it integrates with the existing return line so I can run one or the other if I dont want UV running for servicing or if I want to slow down the uv for protozoa and just adjust the valves so together they equal my desired tank turnover rate. I'm kind of entertaining the idea of just quick and easily running the uv output up & over the back of my display tank to make a closed loop that way. It will then be pointing down into a deadspot in my tank. I can then just keep running the original return but at a slow 200gph or so just to keep a similar flow pattern with the dual output lockline that it has pointing from the middle down & out to each side of the tank

bad pic of tank...lights had been off for ten min. So everything closed up.

 

[JPK_Esquire]

Thanks for the advise, I did mount it vertical. Unfortunately I plumbed it out from the return right back into the return as I couldnt think of another way at the moment. Since its Identical to my return pump and have identical desired flow rates (950gph for algae uv & a out 1000 for 10x turnover on my refugium based system) and since the OUTput plumbing on the UV runs inches away from my teturn plumbing going up to the Display, I think I'm just going to plumb my UV output to run up as my return. Perhaps with a valve or two where it integrates with the existing return line so I can run one or the other if I dont want UV running for servicing or if I want to slow down the uv for protozoa and just adjust the valves so together they equal my desired tank turnover rate. I'm kind of entertaining the idea of just quick and easily running the uv output up & over the back of my display tank to make a closed loop that way. It will then be pointing down into a deadspot in my tank. I can then just keep running the original return but at a slow 200gph or so just to keep a similar flow pattern with the dual output lockline that it has pointing from the middle down & out to each side of the tank

bad pic of tank...lights had been off for ten min. So everything closed up.

Very cool. Running it vertical like that, are you getting any micro bubbles? I switched mine up again (see below) and now I’m getting micro bubbles.

 

[JPK_Esquire]

So another update, I switched the setup again because I’ve read so many places and watched a number of videos saying don’t run the UV from and back into the sump. And since that method was already causing the overheating issues, I went back to the original configuration (off the return pump inline on the way back to the display, hanging upside down horizontally inside the stand over the sump). Flow sensor says approx. 500 gph (520 gph without the UV), which I figure is about 3.3x turnover per hour through the UV. The manufacturer suggests 3.68x on the low side minimum, which is when the bulb has been running for a while. So I figure I figure I am pretty dang close enough.

Mounting the UV upside down horizontally is causing a few micro bubbles though, so now I need to try to figure out how to tackle that problem.

 

[JPK_Esquire]

So scratch the last update. I read multiple places that plumbing upside down could cause problems if the return is turned off, and UV not turned off. Without water in the tube, apparently the UV lamp could melt the quartz tube (Great!). Since the outlets were plumbed down, water would definitely leave the tube.

So the latest setup is run the UV off the return pump, at a diagonal in front of the sump, and into the display. Getting about 500-510 gph, so still close enough.

However, my heating the water issue has returned. This tells me the original water hearing issues likely wasn’t caused by the Sicce pump in the sump, but the UV lamp. My guess is that the 40 watt bulb is just overkill for this volume tank (the Pentair 40W is good up to 260g, but the next smallest down is good only up to 130g, so I am in the middle).
Next up, modify the schedule 2 hours on, 1 off).

 

[Malcontent]

Next up, modify the schedule 2 hours on, 1 off).

Hopefully, you're not doing this to your UV...

 

[JPK_Esquire]

Hopefully, you're not doing this to your UV...

Well...it has been somewhat sporadic. The UV raises the temperature about .5 degree every hour. So I haven't set a schedule yet. I'm guessing that by your post running the UV on and off multiple times is not good for the bulb?

 

[Malcontent]

Well...it has been somewhat sporadic. The UV raises the temperature about .5 degree every hour. So I haven't set a schedule yet. I'm guessing that by your post running the UV on and off multiple times is not good for the bulb?

It's very, very bad.

 

[JPK_Esquire]

It's very, very bad.

While your short concise responses are appreciated, some more explanation would be much more helpful to not only me, but others who may read this thread in the future.