PVC drain size questions.

[aquamann183]

Hello everyone, I am in the process of setting up a 150 gallon tank that has two overflow boxes.

Each box has a 3/4" and 1" hole.

My plan is to use one overflow box as full sypon with gate valve on the 3/4" hole and open channel on the 1" hole. And use the 3/4" hole in the other overflow box for a return, and the 1" hole for an emergency drain.

Questions:

1.) On the drain lines, if I use a reducer coupling to increase the size of the PVC..3/4" to 1" and the 1" to 1.5", will this increase the possible flow through the pipes? Or is the flow limited to the smallest section of the pipe?

2.) Should I also increase the size after the bulkhead all the way to the sump?

3.) Will increasing the size of the drain lines help reduce any sound?

Just seeing what everyone does out there. I don't want to drill the holes bigger. Lol.

Thank you everyone,
Happy reefing! 😁

Sent from my HTC One_M8 using Tapatalk

[tklb]

I might be misunderstanding what you are describing, but wouldn't that leave you with 1 full overflow?

In other words, if water cannot flow between your overflows, your 1st overflow (with Gate Valve & Open Channel) would be the only one sending water to your sump. The other one would fill all the way up, no?

I think in order to do what I think you are trying to do, you would need to fabricate some way for water to flow between the two overflows, essentially turning them into 1 overflow with a single water level.

[aquamann183]

Originally Posted by tklb

I might be misunderstanding what you are describing, but wouldn't that leave you with 1 full overflow?

In other words, if water cannot flow between your overflows, your 1st overflow (with Gate Valve & Open Channel) would be the only one sending water to your sump. The other one would fill all the way up, no?

I think in order to do what I think you are trying to do, you would need to fabricate some way for water to flow between the two overflows, essentially turning them into 1 overflow with a single water level.

Basically yes, one overflow is not actually draining any water, just returning and has an emergency drain.

From what I've heard from other people it's too difficult to maintain the same water level in both boxes If your draining. And you'll constantly be losing your syphon and what not and it won't be a quiet system.

Sent from my HTC One_M8 using Tapatalk

[nereefpat]

I don't like the idea of one overflow just sitting with water in it. You would be better off sealing that overflow, and running the return over the back, IMO.

I converted my reef-ready 125 with duel overflows to a Herbie setup. Each overflow has a syphon and a drain. Returns go over the back of the tank. It has been tough to keep the water levels exactly where I want them, but the system is silent, and I know the emergency drains can handle all the water.

[aquamann183]

Originally Posted by nereefpat

I don't like the idea of one overflow just sitting with water in it. You would be better off sealing that overflow, and running the return over the back, IMO.

I converted my reef-ready 125 with duel overflows to a Herbie setup. Each overflow has a syphon and a drain. Returns go over the back of the tank. It has been tough to keep the water levels exactly where I want them, but the system is silent, and I know the emergency drains can handle all the water.

So you have a syphon with a gate valve and an open channel on both sides?
And with it set up like that, you can maintain the same water height in both overflow boxes?

If I had one side that was return and emergency I could have the return go up to just about the top, then use two 90's to make it go to the bottom of the overflow and then drill a hole right under the water level so I don't get a syphon if power goes out. Then I could run another return over the other side. That would keep water flowing in the overflow boxes.

Yes I would prefer to have drains in both boxes, but from what I've heard from other people they say that it doesn't work out, and that the system isn't quiet.

But you're saying that it does work and it is quiet. So I'm interested in your setup. 😛

Sent from my HTC One_M8 using Tapatalk

[nereefpat]

Yes. Syphon with a gate valve and an open pipe on each side. All 4 pipes are 1".

The heights of water in one side doesn't exactly match the height of water on the other, but that doesn't matter. Also, the height of water does fluctuate a little bit. That also doesn't seem to matter. If the water level is too low in the overflow, there will be noise from water falling over the weir. If the syphon isn't open enough and the water level gets too high, water will trickle into the open channel. That won't make noise as long as the trickle isn't too high of flow. I haven't had a problem with either situation.

I know the two emergency drains can handle all the flow, because I tested it, and because I used to run the tank with two durso pipes. The system is very quiet, and I'm glad I made the switch. Before I got on reef central, I had never heard of a Herbie system (I'm out here in the sticks).

I can snap some pics after work if you want me to.

Edit: is your tank drilled, or are the overflow boxes external? This may change things.

[aquamann183]

Originally Posted by aquamann183

So you have a syphon with a gate valve and an open channel on both sides?
And with it set up like that, you can maintain the same water height in both overflow boxes?

If I had one side that was return and emergency I could have the return go up to just about the top, then use two 90's to make it go to the bottom of the overflow and then drill a hole right under the water level so I don't get a syphon if power goes out. Then I could run another return over the other side. That would keep water flowing in the overflow boxes.

Yes I would prefer to have drains in both boxes, but from what I've heard from other people they say that it doesn't work out, and that the system isn't quiet.

But you're saying that it does work and it is quiet. So I'm interested in your setup. 😛

Sent from my HTC One_M8 using Tapatalk

Pictures would be nice if you don't mind!
Overflow boxes are internal with 2 holes in each. A 3/4" hole and 1" hole in each box.

I really would rather do like what you're saying. I don't want a box that essentially isnt doing anything, lol.


Sent from my HTC One_M8 using Tapatalk

[pisanoal]

To answer you first question, flow is directly related to cross-sectional area. And mass flow has to be conserved. So no, increasing the size of a section of your pipe will not yield more flow, your max flow is limited to your smallest cross-sectional area.

To the second question and third question, I tried this on my setup, but had nothing to compare it to. As stated, it wont help with extra flow, but thought it might help with noise for the open channel. I get a little bit of noise in the pipe at too high a flow, but it goes from vertical to horizontal for several feet, pretty quick out of necessity. If I did it again, id just stay 1".

[aquamann183]

Originally Posted by pisanoal

To answer you first question, flow is directly related to cross-sectional area. And mass flow has to be conserved. So no, increasing the size of a section of your pipe will not yield more flow, your max flow is limited to your smallest cross-sectional area.

To the second question and third question, I tried this on my setup, but had nothing to compare it to. As stated, it wont help with extra flow, but thought it might help with noise for the open channel. I get a little bit of noise in the pipe at too high a flow, but it goes from vertical to horizontal for several feet, pretty quick out of necessity. If I did it again, id just stay 1".

Okay, that makes sense. I thought that the flow was limited to the smallest section pipe.

My tank is 27" deep I believe. Will the water make a lot of noise since it has to fall that far, even if the ends of the PVC are under water?

Sent from my HTC One_M8 using Tapatalk

[pisanoal]

If you keep it vertical or mostly so,it should stay quiet. All depends on how much flow you have in the open channel, and if your siphon stays full siphon

Sent from my VS985 4G using Tapatalk

[CStrickland]

my overflows are set up as one 3/4" return and full siphon 1", one full siphon 3/4 and 1" emergency. Drains are noisy when water and air bang around in the pipe. Once you get it tuned in with the gate valves, you have only water in the full siphons and the emergency will be almost all air with just the barest trickle of water. This is a near silent setup at 900 gph. It does seem to help quiet the drains to upsize the standpipes a little, I have wide ones that are adjustable which also made it easier to set up, instead of cutting the pipe. I don't think you need both an open channel and an emergency, but it is more flood safe.

Also, you might not need to drill for bigger holes if you go that way. Some of the reef ready tanks are drilled with 4 holes of the same size that fit either 1" or 3/4" bulkheads. They come with 2 3/4" and 2 1" because that is the most common setup but you can put 1" bulkheads on the 3/4" ones if you like.

[aquamann183]

Originally Posted by CStrickland

my overflows are set up as one 3/4" return and full siphon 1", one full siphon 3/4 and 1" emergency. Drains are noisy when water and air bang around in the pipe. Once you get it tuned in with the gate valves, you have only water in the full siphons and the emergency will be almost all air with just the barest trickle of water. This is a near silent setup at 900 gph. It does seem to help quiet the drains to upsize the standpipes a little, I have wide ones that are adjustable which also made it easier to set up, instead of cutting the pipe. I don't think you need both an open channel and an emergency, but it is more flood safe.

Also, you might not need to drill for bigger holes if you go that way. Some of the reef ready tanks are drilled with 4 holes of the same size that fit either 1" or 3/4" bulkheads. They come with 2 3/4" and 2 1" because that is the most common setup but you can put 1" bulkheads on the 3/4" ones if you like.

I will just leave the holes at the bulkheads the size they are.

I just thought I could use the one side as drain only, then the other side emergency and return, and then have another return come over the side of the tank.

It is going to be an in wall set up, so a pipe coming over the side will be okay.

This is probably a stupid question, but do you glue the pipe thats inside the overflows together, or just the piping after the bulkhead?

Sent from my HTC One_M8 using Tapatalk

[CStrickland]

I just glue after the bulkhead. The standpipes fit snugly in their bulkhead and it's nice to be able to remove them to flush out the overflow. Because the water slows down in there you'll get some detritus accumulation. Like twice a year I will reach in and lift out the standpipe, all the water rushes out the bottom down the bulkhead, carrying the accumulated crud into a filter sock. I pour a few more gallons to rinse it, and then put the standpipe back in.

My weirs are well sealed so they keep water out of the box if the return pump cuts out. I guess if they didn't I might want a seal on the bulkhead so that the water could only drain to the level of the standpipe, not the floor of the tank. But still then I'd probs fix the weirs so the tank could only drain to below the teeth.

You don't need more than one return. You can put a locline Y on it if you want to split up the flow a bit, but the return flow isn't part of your in-tank current. That all powerheads.

[JMorris271]

^^ +++

Anything wet inside the tank can not glued. Makes it easier to clean. Under the tank needs to be glued is usually a safe bet.

[aquamann183]

Alright, thats what I figured. Not gluing inside the tank.

This is my second tank, started with a 40B, so I didn't have overflow boxes like I do now.

Any other silencing tips for the system?
As soon as the drains leave the bulkhead, should I just use two 45's to get the water to the sump, or is just a 90 okay?

I forgot to mention, but my sump will actually be on the side of the tank, not directly underneath.

Sent from my HTC One_M8 using Tapatalk