Is My UV plumbing ok

[Shirak]

Full return for the UV exit is ideal but you still need a gate valve on the T line that goes to the manifold where I indicated so you can force water through the UV as discussed earlier. Dumping back to the sump is not ideal and the worst case IMO as you end up recirculating sump water. Going back to the return line will work as you are effectively splitting the return and sending a portion through the manifold system and a portion through the UV. They recombine after the manifold and continue to the tank as one. You may find you need to turn up the return pump a little to compensate for the slight increase in back pressure on the pump by restricting the flow to the manifold a little to control flow to the UV. The general consensus with this setup I think is you can run low flow through the UV as a general setting for parasite control but when needed you can run all to most of the flow through the UV for algae or dino outbreak, provided the UV is big enough to handle the flow and your tank turnover through the sump is sufficient. For the UV to work on the return for algae and dino control you need 4x minimum of system volume going through the sump per hour 5-6x would be better but that's a lot of flow and many are running only 3x through the sump these days which will not be enough flow for algae/dino control. If that is the case then a closed loop for the UV would be the only solution.

 

[m.kristoff]

Full return for the UV exit is ideal but you still need a gate valve on the T line that goes to the manifold where I indicated so you can force water through the UV as discussed earlier. Dumping back to the sump is not ideal and the worst case IMO as you end up recirculating sump water. Going back to the return line will work as you are effectively splitting the return and sending a portion through the manifold system and a portion through the UV. They recombine after the manifold and continue to the tank as one. You may find you need to turn up the return pump a little to compensate for the slight increase in back pressure on the pump by restricting the flow to the manifold a little to control flow to the UV. The general consensus with this setup I think is you can run low flow through the UV as a general setting for parasite control but when needed you can run all to most of the flow through the UV for algae or dino outbreak, provided the UV is big enough to handle the flow and your tank turnover through the sump is sufficient. For the UV to work on the return for algae and dino control you need 4x minimum of system volume going through the sump per hour 5-6x would be better but that's a lot of flow and many are running only 3x through the sump these days which will not be enough flow for algae/dino control. If that is the case then a closed loop for the UV would be the only solution.

I wonder if I should also put a check valve on the UV return to prevent all reverse flow?? Valve for sure, and I do like the idea that I can divert all flow to the UV or bi-pass it all together.

 

[Yodeling]

The trend lately has been to do this. I figured I would give it a try. My tank is empty, so I decided to experiment. it's a "little" more efficient than dumping back to the sump which a lot of people do.

a gate valve will solve the problem to balance the flow between the 2 lines.

More than likely i'll either put a valve on it or just run the UV side as the full return

If I understand your plan correctly, you would install a gate valve on your main return (effectively choking off a portion of your main display return and all of the manifold valves) in order to achieve a pressure differential between the UV inlet and outlet. In theory, that could work, but imho it's probably the most complicated way of achieving a pretty simple outcome. You'll end up always having to fight and balance your manifold pressure, god forbid you want to adjust flow through other manifold devices or tweak your return flow. I would stay away from this approach.

P.S. If this is a trend, as you say, I would love to see some links to a successful and trouble-free implementation of this. Personally I doubt it.

 

[Shirak]

I wonder if I should also put a check valve on the UV return to prevent all reverse flow?? Valve for sure, and I do like the idea that I can divert all flow to the UV or bi-pass it all together.

If you are plumbing the UV back to the tank independent of the main return then you would want a check valve on that line. I hope you have a check valve already on the main return after the manifold? If you decided to keep it as is and add that additional gate valve, a check valve on the UV outlet wouldn't do anything except add more back pressure to the UV portion of the line.

 

[m.kristoff]

P.S. If this is a trend, as you say, I would love to see some links to a successful and trouble-free implementation of this. Personally I doubt it.

I have seen a few, but as far as success- who knows. I get the theory. This a new setup so no harm in experimenting.

 

[m.kristoff]

Option A: add Gate/Ball Valve to manifold side.
Pros:
can bypass or direct full flow through UV
Cons:
Balancing the Manifold.- Can be a set and forget at least for me

Option B: Full return going through the UV to the Tank
Pros:
most optimal
Cons:
Reduces flow rates. if I choose to go after algae, Tank turn over would be too high

Option C: Dump it back to the sump
Pros: simple
Cons: not optimal, but does have an effect

 

[Yodeling]

Good summary. The most optimal way is actually to plumb it from DT back to DT. This provides the most flexibility in terms of flow, and targets the tank as opposed to the sump. I have mine running off a pump that's tucked away behind some rocks in the DT. I realize that it's not for everyone in terms of esthetics.

 

[m.kristoff]

Went with plan D!
To ensure the manifold balance, I put the valve after the manifold. I have it turned off so all flow to the tank is going through the UV. I can now take the UV offline and still have manifold and tank flow. Was also trying to preserve some of the existing plumbing

But I think that the flow sensor is just messed up- Still getting odd readings. Double checked it. it is pointed the right way and it is set at 1". The 653 is from the other flow sensor. that seems right. Tank turnover is a little less than 5x's per hour

 

[m.kristoff]

Update: Received my replacement flow sensor from neptune. All is working as expected now. it was a bad sensor