Plumbing question

fredward · Jan 30, 2023

Hi. I got this 70gal used. Drilled for a 1.5” drain, 1” e-drain and 1” return. Herbie type. Was wanting to know if 1.5” for the main drain is optimal or too large. Would it be better or would it work to run the 1” as the main drain and the 1.5” as the e-drain. I have a 30 gal sump and a sicce sdc 6.0 was going to run about 5x turnover so around 500gph after head pressure is accounted for

homer1475 · Jan 30, 2023

I would run it exactly as you have it listed.

The smaller emergency will allow a lot of noise if activated. Which is exactly what you want. If the emergency is activated, making a large noise will alert you to an issue.

1" full siphon(should the emergency be activated and go full siphon) should still be plenty big enough to handle the load should the main become blocked.

DCR · Jan 30, 2023

It will work either way, but I would use the 1.5" for the emergency. A 1" full siphon is plenty for a 70 gal. You will be throttling down severely on a 1.5" full siphon with that small overflow box.

KStatefan · Jan 30, 2023

I would switch the main and emergency also. Depending on your plumbing layout your 500 gph would only require about a 1/2" orifice.

theMeat · Jan 30, 2023

Agreed with the switch for 1” for main drain, 1.5 for emergency.
one inch for full siphon is more than enough, while one inch for emergency is cutting it too close for comfort

homer1475 · Jan 30, 2023

theMeat said:
Agreed with the switch for 1” for main drain, 1.5 for emergency.
one inch for full siphon is more than enough, while one inch for emergency is cutting it too close for comfort

Logically that makes 0 sense.

If a 1" full siphon is plenty, then why would a 1" emergency(goes full siphon if main is blocked) not be enough? Same size pipe in both instances, and both going full siphon.

In my herbie setup I have a 1" main, and 1" emergency. Both provide adequate amount of flow if one is blocked.

theMeat · Jan 30, 2023

homer1475 said:
Logically that makes 0 sense.

If a 1" full siphon is plenty, then why would a 1" emergency(goes full siphon if main is blocked) not be enough? Same size pipe in both instances, and both going full siphon.

In my herbie setup I have a 1" main, and 1" emergency. Both provide adequate amount of flow if one is blocked.

The emergency will flip from full siphon to not full siphon because it has no valve and water will drain below the top of the pipe, sucking air, then have to purge itself of air to become full siphon, then repeat, again and again.
Why use the 1.5 for main/full siphon when the one inch is more than enough? Will be easier to purge and run quieter using the one inch for main drain. Safer to use 1.5 as emergency. A no brainer

homer1475 · Jan 30, 2023

theMeat said:
The emergency will flip from full siphon to not full siphon because it has no valve and water will drain below the top of the pipe, sucking air, then have to purge itself of air to become full siphon, then repeat, again and again.
Why use the 1.5 for main/full siphon when the one inch is more than enough? Will be easier to purge and run quieter using the one inch for main drain. Safer to use 1.5 as emergency. A no brainer

I get that, and thank you for explaining it.

But wouldn't you want it to go full siphon, flush, repeat just for the noise factor to alert you of something going wrong? Least that is how I know something is wrong in my setup.

theMeat · Jan 30, 2023

homer1475 said:
I get that, and thank you for explaining it.

But wouldn't you want it to go full siphon, flush, repeat just for the noise factor to alert you of something going wrong? Least that is how I know something is wrong in my setup.

I see your point and personally would rather know it’s failsafe and flood proof. Could/should have main drain exit an inch or two below water level in sump so it runs quiet. And have the emergency drain end a few inches above the sump water level so it splashes and makes noise.

homer1475 · Jan 30, 2023

theMeat said:
I see your point and personally would rather know it’s failsafe and flood proof. Could/should have main drain exit an inch or two below water level in sump so it runs quiet. And have the emergency drain end a few inches above the sump water level so it splashes and makes noise.

Exactly how I have mine setup actually. The e-drain is a inch or so above the water level so I can hear it crashing. It also empties above the return so it creates bubbles in the display.

Visual, and audible clues as to something going wrong.

theMeat · Jan 30, 2023

homer1475 said:
Exactly how I have mine setup actually. The e-drain is a inch or so above the water level so I can hear it crashing. It also empties above the return so it creates bubbles in the display.

Visual, and audible clues as to something going wrong.

That’s cool. Think most people, including myself, have sump set up so that water from display goes into sump on one side, then skimmer, fuge, whatever else, then on the opposing side return pump. So that water that goes into sump goes through whatever filtration processes you have set up, then returns to display

DCR · Jan 30, 2023

If you do use the 1-1/2" for a full siphon, I recommend reducing it down to 1" after the bulkhead. The 1.5" pipe is bulky to work with and I think you may have a difficult time flushing the air out of a 1.5" full siphon below the gate valve and keeping it quiet. You also will not like the price of a 1.5" gate valve.