Herbie overflow with different size drains?

[I_Got_Crabs]

I want to set up a herbie overflow with a used 65 gallon tank I bought but unfortunately the bottom panel is tempered glass and the holes in the overflow are different sizes (1" and 3/4"). Is there any danger to having my emergency drain be 3/4"?

 

[saltyhog]

I wouldn't think it would be a problem in that size tank. How much volume is your return pump going to move?

I would also think a 3/4" full siphon would handle the return in that size tank. I have 1" returns (Bean Animal) in my tank and my full siphon valve is closed a couple of turns. If so, your other option would be to use the 3/4" as your full siphon and the 1" as the emergency.

Let's see if some of the plumbing experts will chime in. #reefsquad

 

[dbl]

Using the 3/4" as the full siphon and the 1" as the emergency would be my suggestion as well. But yes, it will work the other way as well.

 

[Crabs McJones]

+1 for 3/4 full siphon 1 inch emergency. A 3/4 pipe under siphon can move more water than a 1" gravity fed without a siphon so better to have the big pipe as a backup just in case

 

[Indymann99]

+2 3/4 for primary full siphon drain and 1in for emergency. With a 65g tank you will be fine with a 3/4 full siphon drain.

 

[EricG]

So I have this exact setup on an 80 gallon tank that I just put together. I used the 3/4" for the primary siphon and the 1" for the emergency drain. The problem I am having is the 3/4" drain is very slow and I can not adjust the water level in the overflow from the gate valve. Most of the water is going down the emergency drain and making a lot of noise in the process. The 1" emergency drain has a straight shot down to the sump, but the 3/4" full siphon has (2) 90's plus a gate valve that I bought at a local hardware store. I'm starting to wonder if the pvc gate valve that I got is restricting the water flow? At the moment the valve is wide open and I have a dc return pump that is on the lowest setting

 

[ca1ore]

Sounds like the line is blocked somewhere.

 

[dbl]

+1.

Also, hard to tell in the picture but does that gate valve have metal as the interior of the valve?

 

[Lukas75]

+3 on the 3/4" as the primary, but you'll have to size the pump to that size of drain.

 

[Lukas75]

So I have this exact setup on an 80 gallon tank that I just put together. I used the 3/4" for the primary siphon and the 1" for the emergency drain. The problem I am having is the 3/4" drain is very slow and I can not adjust the water level in the overflow from the gate valve. Most of the water is going down the emergency drain and making a lot of noise in the process. The 1" emergency drain has a straight shot down to the sump, but the 3/4" full siphon has (2) 90's plus a gate valve that I bought at a local hardware store. I'm starting to wonder if the pvc gate valve that I got is restricting the water flow? At the moment the valve is wide open and I have a dc return pump that is on the lowest setting

How low is low on the return pump/what type of pump is it? And can you tell how much water is coming out of the 3/4 inch drain? you might have to remove the union before the sump to get an idea.

 

[doughboy]

EricG- 3/4" pvc can handle 660gph flow via gravity in theory, like if it flows straight down.
it looks like you used 2 90deg elbows, so that will affect the flow. change it to 2 45deg, or if possible, make it go straight down.
the height of the 3/4" tube in the overflow also affects the flow. if you put it too high, flow is reduced. you want it about 1/3 to no more than 1/2 the height of your overflow.

 

[EricG]

+1.

Also, hard to tell in the picture but does that gate valve have metal as the interior of the valve?

All of the interior is PVC

How low is low on the return pump/what type of pump is it? And can you tell how much water is coming out of the 3/4 inch drain? you might have to remove the union before the sump to get an idea.

I do not know how much water is coming out of the 3/4” drain. The bottom of the drain pipe is about 1” below the water. My return pump is a Simplicity 2100 DC pump. I have it currently on the lowest setting, but not sure how much GPH that would produce? It came with the setup that I purchased

EricG- 3/4" pvc can handle 660gph flow via gravity in theory, like if it flows straight down.
it looks like you used 2 90deg elbows, so that will affect the flow. change it to 2 45deg, or if possible, make it go straight down.
the height of the 3/4" tube in the overflow also affects the flow. if you put it too high, flow is reduced. you want it about 1/3 to no more than 1/2 the height of your overflow.

The full siphon drain is about 6-7” below the overflow and the emergency drain is about 1” below. I could change the 90’s to 45’s if that would help.

Thanks for all the help, not sure what I need to do. This is my first tank with a sump underneath. So it’s been quite a learning experience

 

[Lukas75]

All of the interior is PVC
I do not know how much water is coming out of the 3/4” drain. The bottom of the drain pipe is about 1” below the water. My return pump is a Simplicity 2100 DC pump. I have it currently on the lowest setting, but not sure how much GPH that would produce? It came with the setup that I purchased

I can't find a minimum flow rating for it, or any type of percentage, but at a maximum flow of 2100 gph that pump is way more pump than you need. Everything I'm reading says that a 3/4" drain should be able to handle between 350 and 400 GPH. I double checked myself on those numbers on multiple sources. I'm wondering if all the way down that pump is just too much for the job.Has it always run like this? Or is it a recent thing?

 

[EricG]

I can't find a minimum flow rating for it, or any type of percentage, but at a maximum flow of 2100 gph that pump is way more pump than you need. Everything I'm reading says that a 3/4" drain should be able to handle between 350 and 400 GPH. I double checked myself on those numbers on multiple sources. I'm wondering if all the way down that pump is just too much for the job.Has it always run like this? Or is it a recent thing?

This was the pump that the previous owner was using, but I’m not sure how he had his drain setup? He did tell me that he always had the return pump on one of the lowest settings. I’ve looked online but haven’t been able to find much information on the pump itself.

 

[EricG]

I believe I know what the error is. I was looking over the plumbing parts I bought and what I thought was a gate valve is a stop valve. I have a feeling that is what’s causing my issue and restricting flow. None of the big box stores around me stocks a gate valve. Would it be ok to use a ball valve or should I order a gate valve and just wait a few days? I could also change out the 90’s to 45’s if that would make a difference?

Thanks again for the help on this. The image above shows what it looks like fully open.

 

[ReefHog]

Order a full port gate valve. Easier to fine tune than ball valve.

 

[Lukas75]

+1 on the full port valve. And I can't see anything through that valve. I should be able to see right through it if it was open. Fully open looks closed to me. Is it maybe some oddball that the threading is reversed and what you thought was open is closed? That or it's just plain broken.

 

[ca1ore]

Lots of things will affect the flow through a 3/4" siphon - primarily the amount of head pressure that is allowed to build over the open top of the pipe and then the amount of drop from display to sump. I ran a 3/4" as my siphon with no stand pipe inside the overflow (just a screened bulkhead) and 10' of drop to a basement sump and got over 800 gph out of it.

 

[EricG]

Thanks everybody, I did a quick change out to a ball valve from Lowes to fix the issue. I have a full port valve ordered and will replace the ball valve when it comes in. I was able to balance the system with the current setup and the water level in the overflow is just barely hitting the top of the emergency drain.