Plumbing for dual overflow

[DVal]

Hey everybody, looking for some input on plumbing a dual overflow tank. There's a 1in and 3/4 in bulkhead in both overflows (not corner). Im considering running a durso in each overflow box with a return in one and an emergency drain in the other using the 3/4 bulkhead. Id prefer Not to run the return over the top IF possible. Also, should I sticl.to the 3/4in pipe for the return and 1in for the full runs of the drains? Thanks in advance for any input

 

[Snoopy 67]

Durso's get noisy with flow. You can try it. If not satisfied then you get to a Herbie which requires coming back over the top. I use Sea Swirls on mine.

 

[Rjramos]

I would imagine with dual overflows it is probably over a 100gal tank. 1- 3/4” return back up through one overflow is not gonna return what both overflow boxes together have capacity to drain to your sump below. It defeats the purpose of having 2 overflows. A lot of members will chime in and suggest an emergency drain out of 3/4” bulkhead in the overflow. I have a 120gal with dual overflows setup since 2006(14 yrs). I set it up with a durso on each 1” bulkhead, and a split return from the pump coming through the 3/4” bulkheads. This will offer the best turnover rate, if this is what you want. Some will raise concern about something, perhaps a snail clogging your durso, in 14 years it hasn’t happened to me. That’s why there should be a weir at the top of each overflow. If there is concern of a snail climbing over the weir then a lid can be placed to cover the overflow boxes, as I have. Secondly, because you have 2 overflows, if one durso just so happens to clog with something, the other one can serve as emergency and keep the tank from flooding the floor.

 

[DVal]

I would imagine with dual overflows it is probably over a 100gal tank. 1- 3/4” return back up through one overflow is not gonna return what both overflow boxes together have capacity to drain to your sump below. It defeats the purpose of having 2 overflows. A lot of members will chime in and suggest an emergency drain out of 3/4” bulkhead in the overflow. I have a 120gal with dual overflows setup since 2006(14 yrs). I set it up with a durso on each 1” bulkhead, and a split return from the pump coming through the 3/4” bulkheads. This will offer the best turnover rate, if this is what you want. Some will raise concern about something, perhaps a snail clogging your durso, in 14 years it hasn’t happened to me. That’s why there should be a weir at the top of each overflow. If there is concern of a snail climbing over the weir then a lid can be placed to cover the overflow boxes, as I have. Secondly, because you have 2 overflows, if one durso just so happens to clog with something, the other one can serve as emergency and keep the tank from flooding the floor.

How is the noise?

 

[Rjramos]

All of my dursos run quiet. If it gets noisy, it tells me the air vent is clogged with salt deposit. So I simply clean the vent and the water levels off to where it’s supposed to be, mid T to just above submerged T. Properly venting a durso is very important. However you decide to go, whether starting with a small 1/8” hole directly through the cap and working up size, or with a fitting and hose with a valve, you have to be able to clean it periodically. Clean vent, quiet durso.

 

[Addicted2Reef’n]

All of my dursos run quiet. If it gets noisy, it tells me the air vent is clogged with salt deposit. So I simply clean the vent and the water levels off to where it’s supposed to be, mid T to just above submerged T. Properly venting a durso is very important. However you decide to go, whether starting with a small 1/8” hole directly through the cap and working up size, or with a fitting and hose with a valve, you have to be able to clean it periodically. Clean vent, quiet durso.

Any chance you’re still on the forum and cld instruct me on plumbing my dual overflow aqueon magflow? Saw you posted last 2020 just making sure you still here

 

[Addicted2Reef’n]

All of my dursos run quiet. If it gets noisy, it tells me the air vent is clogged with salt deposit. So I simply clean the vent and the water levels off to where it’s supposed to be, mid T to just above submerged T. Properly venting a durso is very important. However you decide to go, whether starting with a small 1/8” hole directly through the cap and working up size, or with a fitting and hose with a valve, you have to be able to clean it periodically. Clean vent, quiet durso.

Any chance you’re still on the forum and cld instruct me on plumbing my dual overflow aqueon magflow? Saw you posted last 2020 just making sure you still here

 

[Rjramos]

Still here, and still running the dual over flows on 120 gal with 2 dursos and 2- 3/4” returns. How can I help? Show me some pics of what you have in these over flow boxes?

 

[Addicted2Reef’n]

 

[Addicted2Reef’n]

 

[Addicted2Reef’n]

Thread 'Help with sump , pipe setup 125 build'
https://www.reef2reef.com/threads/help-with-sump-pipe-setup-125-build.1000591/

 

[Addicted2Reef’n]

Here’s a link to thread I started. I will continue to add stuff as I go

 

[noelfolster]

Still here, and still running the dual over flows on 120 gal with 2 dursos and 2- 3/4” returns. How can I help? Show me some pics of what you have in these over flow boxes?

Hi. I just received a marineland 300 gallon dd dual overflow. I want to plumb it as is. Do you think I could use (2) fluval sea sp4 return pumps. 1 for each return?

 

[Rjramos]

Had to look it up, Fluval sp4, puts out 1800 gph, didn’t see a head pressure chart, which is what you need to see performance in your specific application. The 1800 gph will reduce pushing through the 3/4” bulkhead, riser pipe, nozzle, and height from pump to nozzle. Still I feel, 1 of these pumps per overflow will be more than you need. On my 120, with dual overflows, I am running an external Blueline 70, 1750 gph, through the 3/4” bulkheads and about 6’ of head pressure. In addition to turnover circulation, this pump is also suppling an MRC M1 skimmer through a gated down 3/4” pipe. Works great and been running this way since 2006

 

[DCR]

The corner overflow weirs are going to limit your return flow. I think two SP2's or a single SP4 would be more than adequate and save you some power. I thought the return bulkheads were 1" on the DD's which would still be fine with the above recommendation, but it is really a waste of energy to use an SP4 through a single 3/4" bulkhead. You will probably only get 300-400 gph through a 3/4" connection.