simple Overflow question

[Lucas&kim]

If I wanted to gravity drain 4000gph through my overflow box, assuming my weir could handle it. what size bulkheads would you use and how many? thanks

 

[PYRU]

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[JK47]

If I wanted to gravity drain 4000gph through my overflow box, assuming my weir could handle it. what size bulkheads would you use and how many? thanks

The size of your plumbing heavily depends upon the style of overflow plumbing you choose. Using a gate valve as part of a bean animal, herbie, etc... to achieve full siphon makes all the difference in flow as well as silence. At 4K, two 1.5” lines and a gate valve is plenty. You should look into them or go 2” if you want to just have open channel flow.

 

[Lucas&kim]

The size of your plumbing heavily depends upon the style of overflow plumbing you choose. Using a gate valve as part of a bean animal, herbie, etc... to achieve full siphon makes all the difference in flow as well as silence. At 4K, two 1.5” lines and a gate valve is plenty. You should look into them or go 2” if you want to just have open channel flow.

im going to be using a diy ghost overflow. I think I should have two 3" holes connecting the internal weir through the glass. and then four 2" holes in the external box for drains to the sump. does anyone have experience with this? im wanting to do gravity drains. not siphon.

 

[JK47]

im going to be using a diy ghost overflow. I think I should have two 3" holes connecting the internal weir through the glass. and then four 2" holes in the external box for drains to the sump. does anyone have experience with this? im wanting to do gravity drains. not siphon.

Yes I have experience with making DIY ghost overflows. Have built a few. What you are describing as gravity is open channel. That’s what you’re after. Your plan sounds excellent.

This one has three lines at 1.5” each. At 4K I would rather have four like you are planning. It can keep up just fine but is loud without a gate valve. Definitely do four if it’s always open channel.

The inside of the box connecting the weir to the tank is perfect at two 2” bulkhead fittings as well. Keep the hole on the lower end of the box/weir. Trust me.

 

[Lucas&kim]

Yes I have experience with making DIY ghost overflows. Have built a few. What you are describing as gravity is open channel. That’s what you’re after. Your plan sounds excellent.

This one has three lines at 1.5” each. At 4K I would rather have four like you are planning. It can keep up just fine but is loud without a gate valve. For sure do four if it’s always open channel.

The inside of the box connecting the weir to the tank is perfect at two 2” bulkhead fittings as well. Keep the hole on the lower end of the box/weir. Trust me.

View attachment 1358746

thank you very much you answered all my questions. I like the look of your box. do you sell them? what size should the weir box be for the flow rate?

 

[JK47]

thank you very much you answered all my questions. I like the look of your box. do you sell them?

Thank you. No I don’t sell them. I make them as I need them since few are the same. Your local Tap Plastics can cut everything to order.

I’m not positive but if memory serves correct I paid $80 for materials and cuts for that tank. The front of the weir (the front panel with the teeth) you can get off eBay

 

[JK47]

This one would run around $60. You want to get a box that is the same size as your outer box. Make sure you get one wide enough to accommodate four bulkhead fittings (flange specifically).

https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.com/ulk/itm/192355593685

 

[Lucas&kim]

okay. so I should use
two 2" holes to connect the weir
and four 2" holes for the drains or four 1.5" holes for drains?