UV sterilizer installation advice?

[ShrimpBandit]

I just picked up a UV sterilizer and I plan to plumb it into my dual return line... However, my returns have wye check valves and the sterilizer instructions say that you should not install the unit with any valves between it and the display tank. (Do wye valves even count in this situation?) I think that leaves me with a couple of options:

1. T off of the return line to the UV and then run a drain hose back into the sump (if I do this, does any particular chamber make more sense than another?)

2. T off the return line to the UV and then run a drain hose directly to DT.. which is less than ideal because I have a drilled tank and this hose would be over the rim, unless I plumb a T above the wye valve for the UV return, which also kind of sounds like a PITA.

Thanks in advance.

 

[TexanCanuck]

Congrats on your new purchase!

Before talking about your plumbing questions, I'd start with a little more basic set of questions ...

As you know, for a UV unit to be effective, it needs to have flow through it at a particular rate. If the flow is too low, you won't get enough "turnover" through the unit and therefore it will not be effective at overcoming undesired parasites or algae (because they will proliferate at a rate higher than what you can sterilize). Conversely, having flow rate that is too high will mean that the water won't "dwell" inside the unit long enough to achieve any sterilization at all. To further complicate matters, the amount of "dwell time" needed for sterilization depends on the specific organism you are trying to treat for: parasites require more dwell time than algae (for example).

Therefore, if you really want to get the benefits from your expensive investment in a UV sterilizer, you need work backwards through the plumbing problem:

1) Decide what organism you are really trying to deal with in your UV ... algae OR parasites. It is very difficult to do BOTH in the same unit, unless you dramatically oversize the lamp

2) Based on your treatment objective, use the manufacturer's recommendation to determine what the flow rate THROUGH THE UNIT needs to be

3) Then figure out the plumbing to achieve this flow rate. Remember - the advertised discharge flow rate for a given pump will NOT be the actual flow rate you get through your plumbing!

I just wanted to point this out so you don't make the same mistake I did ... spend a ton of $$ for a treatment solution and NOT get the result I was looking for.

So ... In answer to your plumbing questions:

A) NO ... check valves don't count. In general, the advice about not installing valves between the UV and the tank is really about "throttling valves"

B) the ideal solution is two return pumps and two UV sterilizers, with each pump set to deliver the flow rate required for one function (i.e. algae vs. parasites). For an example of one, see pictures of my setup at the bottom of this post ... I use variable speed pumps and flow meters to tune the flow rate through each UV sterilizer

C) If you can't use separate return pumps, your next best option is creating a "closed loop" ... and a closed loop in the sump works just as well as in the main display tank. The flow rate through the UV is going to be much smaller than the flow rate between the sump and your display ... so while there will be some small amount of "recycling" through the UV, the vast majority of the water processed through the UV will get returned to the main display. Just size your UV and closed loop pump slightly larger than what you'd need for your display tank alone (perhaps assume 20% larger). The discharge of the UV closed loop can go anywhere in your sump, but the further "upstream" it goes the better (simply so it "mixes" more with the unprocessed water and reduces the amount of recycling)

D) if you can't create a closed loop for your UV (i.e. a dedicated pump for the UV that returns back to the same body of water that the pump draws from), then you can connect the UV to a throttling valve off of your main return line to the display ... but remember that the probability of you getting the "right" flow rate through the unit is very small. In this case, you really do need to invest in a flow meter, or spend the extra time to measure the flow manually (using a bucket test) when you set it up for the first time.

Here's what my setup looks like:

 

[FishGeist]

I routed (Hard Plumbed) all return flow through the UV. Used plenty of gate valves and unions. Mine has a bypass, where I can close the 2 valves going into the UV (send + return) and open the 3rd bypass valve whilst I change the Bulb/Sleeve.

 

[ShrimpBandit]

Congrats on your new purchase!

Before talking about your plumbing questions, I'd start with a little more basic set of questions ...

As you know, for a UV unit to be effective, it needs to have flow through it at a particular rate. If the flow is too low, you won't get enough "turnover" through the unit and therefore it will not be effective at overcoming undesired parasites or algae (because they will proliferate at a rate higher than what you can sterilize). Conversely, having flow rate that is too high will mean that the water won't "dwell" inside the unit long enough to achieve any sterilization at all. To further complicate matters, the amount of "dwell time" needed for sterilization depends on the specific organism you are trying to treat for: parasites require more dwell time than algae (for example).

Therefore, if you really want to get the benefits from your expensive investment in a UV sterilizer, you need work backwards through the plumbing problem:

1) Decide what organism you are really trying to deal with in your UV ... algae OR parasites. It is very difficult to do BOTH in the same unit, unless you dramatically oversize the lamp

2) Based on your treatment objective, use the manufacturer's recommendation to determine what the flow rate THROUGH THE UNIT needs to be

3) Then figure out the plumbing to achieve this flow rate. Remember - the advertised discharge flow rate for a given pump will NOT be the actual flow rate you get through your plumbing!

I just wanted to point this out so you don't make the same mistake I did ... spend a ton of $$ for a treatment solution and NOT get the result I was looking for.

So ... In answer to your plumbing questions:

A) NO ... check valves don't count. In general, the advice about not installing valves between the UV and the tank is really about "throttling valves"

B) the ideal solution is two return pumps and two UV sterilizers, with each pump set to deliver the flow rate required for one function (i.e. algae vs. parasites). For an example of one, see pictures of my setup at the bottom of this post ... I use variable speed pumps and flow meters to tune the flow rate through each UV sterilizer

C) If you can't use separate return pumps, your next best option is creating a "closed loop" ... and a closed loop in the sump works just as well as in the main display tank. The flow rate through the UV is going to be much smaller than the flow rate between the sump and your display ... so while there will be some small amount of "recycling" through the UV, the vast majority of the water processed through the UV will get returned to the main display. Just size your UV and closed loop pump slightly larger than what you'd need for your display tank alone (perhaps assume 20% larger). The discharge of the UV closed loop can go anywhere in your sump, but the further "upstream" it goes the better (simply so it "mixes" more with the unprocessed water and reduces the amount of recycling)

D) if you can't create a closed loop for your UV (i.e. a dedicated pump for the UV that returns back to the same body of water that the pump draws from), then you can connect the UV to a throttling valve off of your main return line to the display ... but remember that the probability of you getting the "right" flow rate through the unit is very small. In this case, you really do need to invest in a flow meter, or spend the extra time to measure the flow manually (using a bucket test) when you set it up for the first time.

Here's what my setup looks like:

This is super helpful. Here's what I've got:

My return pump powers the dual return lines - it's rated for 1900gph, but I run it at 40% power, so it's actually closer to 760gph before I factor in the head pressure.

I have a second pump on hand that is adjustable up to 714gph. It's used mainly for faster water changes, but I certainly wouldn't be opposed to repurposing it.

The UV itself is recommended to be run at 110gph for parasites and 240gph for algae.

If I plumb it off my current return pump, I'd clearly have to throttle the flow from the manifold to the UV. If I use my extra pump or buy another/smaller one, I can do the closed loop off the sump thing and adjust for the UV accordingly.

Could it be that the easier option is also the more effective one?!

 

[TexanCanuck]

It sounds like it to me!

By using the smaller pump to create a dedicated closed loop for the UV within the sump itself you get to:

1) Avoid cutting into your existing return line plumbing (and potentially create more problems)
2) Get more control over the flow rate in the UV loop and therefore have a better chance of getting the results you want
3) Be able to power the UV independently of the return pump (so you can disassemble and clean the UV sterilizer for routine maintenance without having to shut down all the flow to your sump)

Final thought: with a closed loop like this in your sump it makes it really easy to use a "bucket test" to prove what the actual flow rate is through the UV unit and fine-tune your setup when needed.

 

[ShrimpBandit]

It sounds like it to me!

By using the smaller pump to create a dedicated closed loop for the UV within the sump itself you get to:

1) Avoid cutting into your existing return line plumbing (and potentially create more problems)
2) Get more control over the flow rate in the UV loop and therefore have a better chance of getting the results you want
3) Be able to power the UV independently of the return pump (so you can disassemble and clean the UV sterilizer for routine maintenance without having to shut down all the flow to your sump)

Final thought: with a closed loop like this in your sump it makes it really easy to use a "bucket test" to prove what the actual flow rate is through the UV unit and fine-tune your setup when needed.

Awesome. Thanks for the guidance! Much appreciated!

 

[Projects with Sam]

You can plumb it so its adjustable too.

This is a photo of my basic manifold for the UV. This is mounted to the top of my stand (blow pics). The clear tube goes to my pump the valve on the bottom is extra, for servicing, the two barbed hose fitting is where the UV goes. This setup allows me to push a small trickle or all the water through the UV without two pumps of any fancy stuff. Flow meters would be nice but this is enough to get by.


its nice because I pop a button and twist and out comes the bulb for servicing.