Need Some Drain & Sump Wisdom

[Coral reefer]

So we will be saving our money and not getting a new overflow box. Proceeding with keeping the internal overflow and modifying the existing drilled holes for the drains (and possibly use one for the return). @a.little.hypertonic seems reluctant about drilling new holes in the tank.

I currently have a pvc adapter on order to switch the larger pipe to a standard 1¼" pipe under the tank. I'm going to keep the "bulkhead" that came with the tank so I can utilize the existing plumbing inside the overflow.

I haven't had a chance to test the drainage capability of a single 1/2 outlet. That's still next on the list. If it is able to handle the full flow, then that may seal the deal and just go with the larger pipe as the main drain and a single emergency drain. Then use the other 1/2 for the return. If she says screw it, I want dual returns drilled in, then bean animal it is!

Usually people use the small drain as a full siphon with gate valve and the larger as a backup.

 

[ReyDeFarts]

Usually people use the small drain as a full siphon with gate valve and the larger as a backup.

I mentioned it earlier, but why would I want to go that route? They designed the tank for the larger pipe to be the primary. Why would I do it differently. If I'm able to confirm that the small drain cannot handle it, I don't mind doing it that way, I just don't understand why I'd choose to go that route.

 

[Coral reefer]

are you going to use a gate valve to make it quiet? If so you want the bigger drain as the emergency. Siphon make it handle more flow, so the small one can ideally handle the flow and if it clogs you have a much bigger one that can handle it gravity style. Not sure why you wouldn’t do it that way honestly.

 

[Coral reefer]

I mentioned it earlier, but why would I want to go that route? They designed the tank for the larger pipe to be the primary. Why would I do it differently. If I'm able to confirm that the small drain cannot handle it, I don't mind doing it that way, I just don't understand why I'd choose to go that route.

How are you sure what the design was? Could be 2 returns and one big drain

 

[ReyDeFarts]

are you going to use a gate valve to make it quiet?

I was/am on the fence about just using a ball valve. Mainly because I was looking at the larger drain as the primary and they are a bit pricey. So I figured I'd dial it in with the pump controller and ball valve.

If so you want the bigger drain as the emergency. Siphon make it handle more flow, so the small one can ideally handle the flow and if it clogs you have a much bigger one that can handle it gravity style. Not sure why you wouldn’t do it that way honestly.

I honestly don't know the answers to the best approach. Heavily relying on wisdom like yours to make the right choice. It just doesn't make sense to me why I wouldn't be using the larger drain as the primary since it's designed to be that way. If the small drain can handle the full flow in an emergency. I have not yet confirmed that though. My ignorance on this is showing, I know. Please bear with me. My logic is a bit scrambled. Lol

Also, after talking with my wife, she really doesn't want to drill into the tank nor spend more on getting a new overflow. I kind of figured we would be going that route. Now I'm banking on only two drains and a single return.

So with that in mind, and adapting my approach to mirror how you would do it, the small drain would be my primary and the larger one my emergency. I would be seeking to get full flow out of the ½" primary and zero flow out of the emergency, correct? The emergency also would be above the water level so it would audibly alert us to an issue, correct?

Looking at the chart that Marcos posted earlier, it looks like the ½" drain would be able to handle approx. 200gph. A ½" gate would be much less expensive for that size!

 

[ReyDeFarts]

How are you sure what the design was? Could be 2 returns and one big drain

I looked up their plans and sales sheet. It's a primary durso drain with an emergency and a single return. The overflow has a single port for the return. I'm sure it could be plumbed to split the return though. I thought about that.

 

[Coral reefer]

I would not use a ball valve. Gate valve is way easier to dial in. I always look at the second drain as and emergency, but in reality I send as little water as possible through that drain. You can get the siphon just right sometimes where the water level stays above that pipe and below the emergency, but it’s REALLY HARD

 

[ReyDeFarts]

Here's a snippet from a sales sheet

"Herbie drain system with extra-large drain circumference of 1.25" for high speed and silent operations" - The pictures I've seen show the larger drain as the primary.

 

[ReyDeFarts]

I would not use a ball valve. Gate valve is way easier to dial in. I always look at the second drain as and emergency, but in reality I send as little water as possible through that drain. You can get the siphon just right sometimes where the water level stays above that pipe and below the emergency, but it’s REALLY HARD

Hmmm... so if I understand what you're saying and a few others stated here, I would want some water going through my secondary anyway? That helps control the actual water level? So I would not want that above the water line in the sump either.

 

[derek_SR]

Hmmm... so if I understand what you're saying and a few others stated here, I would want some water going through my secondary anyway? That helps control the actual water level? So I would not want that above the water line in the sump either.

I would extend REALLY HARD to basically impossible - even if you ARE able to get it absolutely spot on, flow through the pump and/or pipes will slowly change over time, so it's inevitable that it will fall out of balance. The reality is the water level with always either be slowly falling or slowly rising in the overflow box - you want to use the gate valve to tune it so that the water is SLOWLY rising (return flow slightly higher than main drain flow) and you get a "trickle" down the 2nd drain (aka - the trickle drain).

Getting this right is the key to a quiet overflow and I'm still surprised at how many people don't have theirs set up like this!

If the water level in the box is too low (return flow less than main drain flow, so water falls) you get splashing and gurgling. If the water level is too high too fast (return flow much higher than main drain flow) you get too much water going down the 2nd drain which is also usually noisy (though you can use tricks to quiet this down - like elbows and mufflers - these things aren't necessary if you tune it to be truly just a trickle).

 

[Coral reefer]

Hmmm... so if I understand what you're saying and a few others stated here, I would want some water going through my secondary anyway? That helps control the actual water level? So I would not want that above the water line in the sump either.

Pretty much. I always leave the trickle drain above water line in sump. Allows the air in the pipe to move freely rather than getting trapped and burped out the bottom

 

[ReyDeFarts]

I would extend REALLY HARD to basically impossible - even if you ARE able to get it absolutely spot on, flow through the pump and/or pipes will slowly change over time, so it's inevitable that it will fall out of balance. The reality is the water level with always either be slowly falling or slowly rising in the overflow box - you want to use the gate valve to tune it so that the water is SLOWLY rising (return flow slightly higher than main drain flow) and you get a "trickle" down the 2nd drain (aka - the trickle drain).

Getting this right is the key to a quiet overflow and I'm still surprised at how many people don't have theirs set up like this!

If the water level in the box is too low (return flow less than main drain flow, so water falls) you get splashing and gurgling. If the water level is too high too fast (return flow much higher than main drain flow) you get too much water going down the 2nd drain which is also usually noisy (though you can use tricks to quiet this down - like elbows and mufflers - these things aren't necessary if you tune it to be truly just a trickle).

Thanks for the descriptive explanation. Would I want a valve on the trickle drain at all? If that's meant to be the emergency, it should be fully open at all times right?

Pretty much. I always leave the trickle drain above water line in sump. Allows the air in the pipe to move freely rather than getting trapped and burped out the bottom

Oh! It doesn't make a bunch of splashing noise though? That would be my concern.

Also...I seriously appreciate you guys helping me get this through my thick ass head!

 

[Coral reefer]

It is not super loud since it’s the smallest possible flow you can get going down it. No valve on the trickle

 

[derek_SR]

Thanks for the descriptive explanation. Would I want a valve on the trickle drain at all? If that's meant to be the emergency, it should be fully open at all times right?


Oh! It doesn't make a bunch of splashing noise though? That would be my concern.

Also...I seriously appreciate you guys helping me get this through my thick ass head!

It's not technically an emergency drain - if your main drain clogs, your overflow box is going to...overflow (unless your 2nd drain is larger than your main drain - which is why @Coral reefer suggests using the big drain as the 2nd drain). A true emergency drain is a 3rd drain.

 

[RandyC]

Usually people use the small drain as a full siphon with gate valve and the larger as a backup.

I would not use a ball valve. Gate valve is way easier to dial in. I always look at the second drain as and emergency, but in reality I send as little water as possible through that drain. You can get the siphon just right sometimes where the water level stays above that pipe and below the emergency, but it’s REALLY HARD

that’s what I’ve been trying to tell you too!

Not sure where that other chart is from, but here are the rigid pvc flow rates I use.

From:

#1 FlexPVC®.com Water Flow Charts Based on Pipe Size (GPM/GPH) ie, How much water can flow through Sch 40 Pvc Pipe Size 1/2" 3/4" 1" 1.5" 2" 2.5" 3" 4" 6"

Water Flow Volume for a given pipe size based on charts, tables, formula, nomograph, & experience.

flexpvc.com