Dual overflow with Standpipe

[ReefStar]

I have a dual overflow and installed 2 Durso Standpipes. I have only one problem. 95% of the water drains from one of the standpipes. 5% from the other standpipe. I have examined the standpipes and they look like they are exactly the same height. They sit next to each other in the overflow, which is inside the tank. What do I need to do to equalize the water between the two drains?

Thanks!

 

[ChrisIsBored]

Are both the overflows the same sized diameter?

If one is smaller... you could do what I did with my tank and just have the smaller one open. I have so much water being pushed into the overflows though that it's not a problem.

 

[ReefStar]

Chrisisbored.

I see the overflow on your site, where you have a second PVC cut smaller than the standpipe. With this solution, do you get any noise?

 

[ChrisIsBored]

The only noise is related to the falling water at the top of the overflow(which isn't as bad now after I put an acrylic cover on top) and at the sump. I haven't added my baffles to the sump yet so hopefully when I do that it won't be as noisy.

Other than that.. it's not too bad.

 

[teeljay]

hmmm....as long as all the water gets down the drains, does it matter that the flows are unequal??
Mine has unequal flows (not 95/05, more like 60/40) but I see no problems with the situation...it all goes back to the sump.

 

[Karm40]

I have dual overflows and all the water goes down one of them. I decided to accept this and just use the second in case the first one gets clogged, or some other kind of emergency.
I have an acrylic cover too and the overflow is virtually silent.
Maybe yours measure the same height, but when they are inserted or when the elbows are put on, that accounts for the difference in the height?
m

 

[reefland]

Having two standpipes in a single chamber is tricky to tune. I like the idea of a single primary pipe and a secondary pipe as a backup as Karm40 suggests.

If you use a single pipe and it handle the flow, then you don't have enough flow to keep both pipes busy. Increasing the flow (larger pump) my be an option.

Just for kicks remove both end caps so the top is open. What happens then? They will both run louder I think, but I wonder if you will still have one pipe taking all the water.

The pipe that doesn't seem to be doing much. Does it have a longer run to the sump? more turns/elbows than the other? is it submerged in the sump deeper than the other?

 

[ReefStar]

Richard,

I took the endcaps off from both standpipes and water flowed pretty even between the two standpipes. Does this mean the holes in the endcaps are not equal, or is simply the height of the standpipe?

Also, both drains are identical runs to the basement, side by side.

How do I know if I am at full capacity on my overflow vs the return pump,which is a Iwaki 55RLT.

If I added a second pump, or larger pump, should the second standpipe start accepting water?

nothing is easy...

 

[ReefStar]

Richard,

I took the endcaps off from both standpipes and water flowed pretty even between the two standpipes. Does this mean the holes in the endcaps are not equal, or is simply the height of the standpipe?

Also, both drains are identical runs to the basement, side by side.

How do I know if I am at full capacity on my overflow vs the return pump,which is a Iwaki 55RLT.

If I added a second pump, or larger pump, should the second standpipe start accepting water?

nothing is easy...

 

[reefland]

I took the endcaps off from both standpipes and water flowed pretty even between the two standpipes. Does this mean the holes in the endcaps are not equal, or is simply the height of the standpipe?

I think its worth trying to make the holes bigger or simpley just add more holes to the one slurping up all the water.

How do I know if I am at full capacity on my overflow vs the return pump,which is a Iwaki 55RLT.

That part is hard to tell. If your feet get wet you know you passed your capacity. :lol: You can look at the water level in the tank, if your center brace is getting wet the water level is high (to much flow). Which you need to modify the overflow wall to either remove some teeth or make the teeth spacing wider.

I can assure you a Iwaki 55 will not be pushing a dual 1 inch overflow system. I use an Iwaki MD70RLT and it's handled with ease.

If I added a second pump, or larger pump, should the second standpipe start accepting water?

It should. To me its acting like you don't have enough flow to keep both pipes busy. As you clearly have shown a single pipe was able to process your entire turnover rate.

nothing is easy...

Actually this is pretty easy once you understand it. Your setup is slightly complicated with such a long drop to the sump.