Aquarium Plumbing for Two Overflows Questions

[Zxandak]

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)?

By slots do you mean the teeth on the overflow boxes?

 

[Smo]

By slots do you mean the teeth on the overflow boxes?

Yes, the open slot widths and number of slots.

 

[Zxandak]

I can't get their exact measurement but 3 slots together is about 1 inch and theres 23 teeth total, not sure if it matters but there is also teeth halfway down and more toward the bottom of the overflow that flows up and over the wall like the teeth at the top.

 

[Wieloch89]

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?

1 1/4” inside of the overflow. It wouldn’t hurt to do it under the tank as well but you can if you like.

 

[Smo]

I can't get their exact measurement but 3 slots together is about 1 inch and theres 23 teeth total, not sure if it matters but there is also teeth halfway down and more toward the bottom of the overflow that flows up and over the wall like the teeth at the top.

What we need to know is the width of the slots that the water flows thru at the top weir. We’ll ignore for the moment the slots towards the bottom of the overflow box.

 

[scott11106]

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.

i agree, i would not "T" the drains to avoid flood if something block one drain.

 

[Zxandak]

What we need to know is the width of the slots that the water flows thru at the top weir. We’ll ignore for the moment the slots towards the bottom of the overflow box.

Not the best at using a measuring tape but I believe they are 3/16th inch for each hole with 23 total on the top.

 

[Zxandak]

i agree, i would not "T" the drains to avoid flood if something block one drain.

Yea I've read about bad stories with T on the drain, I was asking about putting it on the return otherwise I would need to use 2 separate pumps?

 

[Susan Edwards]

I have the same set up, same size tank. Each overflow is set for 1 drain, 1 return. Just got most of the plumbing. Rest coming in next week. Sump allows for 2 drains so I'll T the return line, and add a manifold. Spent months drawing out the plumbing! Hopefully it all works

 

[Wieloch89]

Yea I've read about bad stories with T on the drain, I was asking about putting it on the return otherwise I would need to use 2 separate pumps?

Perfectly ok to “T” the return. Common practice.

 

[Reef-junky]

Perfectly ok to “T” the return. Common practice.

Yes if you want to kill your return flow. Water doesn’t like hitting a wall and then being forced to split. If this is going to be done the T should be set up so the water isn’t forced to split.

 

[Reef-junky]

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.

You know a 3/4” pipe handles less flow then a 1” pipe right? It is a bad plan to have a tank set up where the emergency drain can handle less flow then the main drain. Ting off the overflow is asking for a flood as many have stated.

 

[Reef-junky]

I would not set up a durso overflow. That is the worst overflow you can have. What you can do is set up a Herbie style overflow where the main drain is the 3/4” pipe and the emergency is the 1”. This is probably not ideal but would work with what you have then pipe the return over the top of the DT. As others have stated.

 

[Zxandak]

I would not set up a durso overflow. That is the worst overflow you can have. What you can do is set up a Herbie style overflow where the main drain is the 3/4” pipe and the emergency is the 1”. This is probably not ideal but would work with what you have then pipe the return over the top of the DT. As others have stated.

So for that idea I would have both overflows functioning in that way with the 1" being the emergency and main is the 3/4" then use 1 pipe going over and up the back of the tank into the display?

 

[Zxandak]

Anyone have recommendation for software to draw up these ideas? Only tried paper and pen in the past but got confusing.

 

[Fin]

You can join the drains, if you choose to do so. I did. As long as you tie the two 1" drains to a larger size main drain. I used 1½". I plumbed my 140 that way and it ran for 11 years with no incident. It was quiet also. You can see where the two 1" drains are joined at the 1½" T with two 1" to 1½" bushings.

You can tie the returns together, but it works better if you use a Y connector and not a T. This is an old picture of the way I joined the two 3/4" returns on the 140. It had 2 Mega-Flow overflows, probably similar to what you have.

And this was the tank that was plumbed that way.

 

[mjlash22]

You know a 3/4” pipe handles less flow then a 1” pipe right? It is a bad plan to have a tank set up where the emergency drain can handle less flow then the main drain. Ting off the overflow is asking for a flood as many have stated.

Yes I do understand. Many tanks that are pre-plumbed have the emergency drain smaller than the main drain. Since @Zxandak is custom plumbing his, he can surely decide in which route he wants to go, but I think it's safe to say, to matter which drain you use as the main vs emergency, it can be sucessfully done. My current tank would be my own example. 2+ years, 0 issues.

 

[Smo]

There are folks that have had floods and there are folks that are about to have floods. Then again, there are a few folks that avoid floods by designing a fail-safe drain and return system.

 

[Reef-junky]

Yes I do understand. Many tanks that are pre-plumbed have the emergency drain smaller than the main drain. Since @Zxandak is custom plumbing his, he can surely decide in which route he wants to go, but I think it's safe to say, to matter which drain you use as the main vs emergency, it can be sucessfully done. My current tank would be my own example. 2+ years, 0 issues.

And what happens when the emergency drain has to take on the full flow of the tank and can’t handle it? That set up is just asking for a flood. Bad design and bad idea. It’s called an emergency drain for a reason. Time is immaterial you could run 10 years without a problem then one day you end up with a flood because the emergency drain couldn’t handle the flow that it needed to. Are going to still run the same set up after that and say will it was good for 10 years?

 

[Reef-junky]

You can join the drains, if you choose to do so. I did. As long as you tie the two 1" drains to a larger size main drain. I used 1½". I plumbed my 140 that way and it ran for 11 years with no incident. It was quiet also. You can see where the two 1" drains are joined at the 1½" T with two 1" to 1½" bushings.

You can tie the returns together, but it works better if you use a Y connector and not a T. This is an old picture of the way I joined the two 3/4" returns on the 140. It had 2 Mega-Flow overflows, probably similar to what you have.

And this was the tank that was plumbed that way.

To me this creates a perfect spot to end up plugging your pipe. It’s not giving you any advantage by combining the two drains but it adds risk. You could say that’s what the emergency is for but why design something that way in the first place? I would rather minimize the risk of the drain plugging to begin with.