Aquarium Plumbing for Two Overflows Questions

[Zxandak]

I have a tank that is about 72 inches long and 18 inches wide with two overflow boxes on the back wall with each having a 1 inch hole and a 3/4 inch hole in the bottom of the glass. I have a sump with two 1 inch drain holes that I will most likely be using.

My question is how to setup the overflow for the best possible safety and quietest. I had it setup a few years ago but it got very noisy at times and wanted to get some help before I pipe it a second time. Most other threads I've seen involved larger pipes than what I have or more holes.

If you got any questions for me or need pictures let me know.

 

[mjlash22]

Sound like you will have to connect the plumbing from the 2 overflows by a T fitting then into your sump. 1 T fitting for the 1" and 1 T fitting for the 3/4" pipes. The 1" is more than likely meant for your main overflow down pipe where the 3/4" is more than likely meant for your emergency overflow down pipe. You can use a ball or gate valve for each T fitting to control the flow which will help with the noise. You should really only need a valve on the main pipe, but it wouldnt hurt to do both.

 

[Wieloch89]

I would use and adapter from 1” to 1 1/4” coming off of the bulkhead for the stand pipes. If not the pipe will back up and create a siphon, once the water level gets down far enough the siphon will break you’ll hear a nasty gurgling sound echoing through the pipe over and over and over again.

 

[Wieloch89]

DO NOT CONNECT THE DRAINS WITH A “T”. They are meant to be separate. You most likely have a set up for 2 durso drains.

 

[mjlash22]

DO NOT CONNECT THE DRAINS WITH A “T”. They are meant to be separate. You most likely have a set up for 2 durso drains.

Is there a reason? I have seen this done on several tanks with no issues.

 

[Zxandak]

Ok so take the two 1 inch drains add an adapter to make them 1 1/4 inch coming off the stand then use the durso method? That's almost what I did before but I left the 1 inch drains as is and didn't add any adapters to make it bigger.

 

[Wieloch89]

Because it can cause the two separate stand pipes to draw a siphon off of each other making it noisy. He has a drilled tank for a vented drain, you don’t want a siphon. The plumbing with the drains connected by a T are for tanks that aren’t drilled and need a manual overflow that required a siphon.

 

[mjlash22]

Because it can cause the two separate stand pipes to draw a siphon off of each other making it noisy. He has a drilled tank for a vented drain, you don’t want a siphon. The plumbing with the drains connected by a T are for tanks that aren’t drilled and need a manual overflow that required a siphon.

So 4 durso's? 2 per?

 

[Wieloch89]

Ok so take the two 1 inch drains add an adapter to make them 1 1/4 inch coming off the stand then use the durso method? That's almost what I did before but I left the 1 inch drains as is and didn't add any adapters to make it bigger.

Exactly. So the stand pipe in your overflow box will be 1 1/4”. You could get away with 1” if it will fit but 1 1/4” allows for more water flow and will be much quieter.

Once you make your 2 90 degree bends at the top and cap off the stand pipe turn your return pump on. Then start with a small drill bit and make a progressively larger hole in the cap at the top until the water drains without creating a siphon.

 

[Wieloch89]

So 4 durso's? 2 per?

1 drain and 1 return per overflow box.

 

[mjlash22]

1 drain and 1 return per overflow box.

Ahhh...yes. Completely forgot about the need for a return!

 

[Wieloch89]

Ahhh...yes. Completely forgot about the need for a return!

Hahaha you just have to find toddler to employ to constantly cup the water back into the tank.

 

[Zxandak]

I can T the return line though right?

 

[Wieloch89]

I can T the return line though right?

Absolutely. I recommend adding a few extra valves to make a manifold for future upgrades.

 

[Pntbll687]

So 4 durso's? 2 per?

2 dursos

The setup is for one durso drain in each overflow, and one return line in each. This setup is done on almost all reef ready tanks from marineland/Perfecto.

I have seen some people use one overflow as a Herbie setup, and the other as two returns.

 

[Zxandak]

Absolutely. I recommend adding a few extra valves to make a manifold for future upgrades.

Yea I was already looking at doing a manifold similar to the BRS 150. Thanks for the help.

 

[Zxandak]

Exactly. So the stand pipe in your overflow box will be 1 1/4”. You could get away with 1” if it will fit but 1 1/4” allows for more water flow and will be much quieter.

Once you make your 2 90 degree bends at the top and cap off the stand pipe turn your return pump on. Then start with a small drill bit and make a progressively larger hole in the cap at the top until the water drains without creating a siphon.

Sorry, to clarify would it be good to have the adapter for 1 1/4 inch inside the overflow only or should I have an another adapter below the stand side bulkhead to covert it to 1 1/4 all the way to the sump?

 

[Smo]

I agree with Wieloch89. This tank appears to have been designed for two Dursos and two returns. If you T the returns together you increase the risk of a flood. First, it will be very difficult to balance the flow and two, any restriction caused by debris means you have no backup.
Your easiest solution is to use larger Durso standpipes (1 1/4” or larger) reducing to the 1” bulkheads, with each drain pipe leading separately to the sump. Depending on the rate of return flow the noise level may be acceptable.
The alternative is repurposing at least one of the 3/4” bulkheads to use as a full syphon drain controlled by a gate valve. Use the 1” bulkhead in the other overflow as an emergency drain and the 1” bulkhead in the full syphon overflow as a Durso (otherwise called an open channel for a BeanAnimal drain system). This gets complicated. Note, under normal operation you would only have flow down a single overflow. And you would only have a single return.
There are other variations of this scheme but it would require an additional bulkhead in each overflow to install a “balance pipe” between the two...an entirely new level of complexity.

 

[Zxandak]

I agree with Wieloch89. This tank appears to have been designed for two Dursos and two returns. If you T the returns together you increase the risk of a flood. First, it will be very difficult to balance the flow and two, any restriction caused by debris means you have no backup.
Your easiest solution is to use larger Durso standpipes (1 1/4” or larger) reducing to the 1” bulkheads, with each drain pipe leading separately to the sump. Depending on the rate of return flow the noise level may be acceptable.
The alternative is repurposing at least one of the 3/4” bulkheads to use as a full syphon drain controlled by a gate valve. Use the 1” bulkhead in the other overflow as an emergency drain and the 1” bulkhead in the full syphon overflow as a Durso (otherwise called an open channel for a BeanAnimal drain system). This gets complicated. Note, under normal operation you would only have flow down a single overflow. And you would only have a single return.
There are other variations of this scheme but it would require an additional bulkhead in each overflow to install a “balance pipe” between the two...an entirely new level of complexity.

That's interesting I was looking at BeanAnimal but didn't think it was possible with my already drilled tank.

 

[Smo]

That's interesting I was looking at BeanAnimal but didn't think it was possible with my already drilled tank.

It is but can get complicated in a hurry. First question is to decide if you can get enough flow down a single overflow. Do you know the linear length (width of slots x number of slots)?