Let’s talk about Manifolds

[galantra]

So, I seen many photos and see the talk about people using manifold. And I would equally like to add one into my new setup. But I have some questions

1. How do you determine the flow? Specially to the tank or into the items you have using the manifold ?Is it a guessing game?

2. Return pump how many more gph would you need?

3. Using valves to decrease flow how do I not over use the return pump?

4. How does it affect the head pressure or distance?

Anyone has pics and uses to help me out?

 

[naterealbig]

So, I seen many photos and see the talk about people using manifold. And I would equally like to add one into my new setup. But I have some questions

1. How do you determine the flow? Specially to the tank or into the items you have using the manifold ?Is it a guessing game?

2. Return pump how many more gph would you need?

3. Using valves to decrease flow how do I not over use the return pump?

4. How does it affect the head pressure or distance?

Anyone has pics and uses to help me out?

Hi there,

1. So let's start here. Determine how many lines you want to run off of your manifold. How many pieces of ancillary equipment are you planning on running?. This might be an external skimmer, carbon reactor, gfo reactor, etc. I would take the number of items you plan on running and add 2 or 3. This is the total amount of lines you want on your manifold.

1a. Next you want to determine the flow you will need for each line. For a carbon or gfo reactor, maybe 2x - 3x system turnover per hour. Manufactures of good external Skimmers and UV sterilizers will tell you the ideal flow rate they need.

1b. For the two or three extra, plan on a higher flow rate per line. Maybe 200-300 gph each.

2. Calculating the return pump size. There are a thousand factors, but here is an easy way to make an educated guess. Add the total possible amount of flow for your manifold (Add anticipated flow rate for each line coming off). Then add the desired flow you want in the display to this number. Multiply your total by ~ 2, and that is the size return pump you will need.

3. If you're using a DC pump, it's easy. Just dial the flow as necessary. For non controllable pumps you can do two things. A - put a gate valve downstream of your manifold and upstream of the return to the display. Close and open the gate valve as necessary for desired flow. Using a valve this way will not hurt the pump. The other option is use one of your manifold lines (or t-off of your return plumbing and (using a gate valve) simply divert some of the water from your return back to your sump.

4. It's hard to say. Every inch of piping, and every fitting you add will create additional head pressure in your plumbing system. We can use Bernoulli's Equation and data from one of my fluid mechanics books to put together realistic numbers if you really need them. Although, you likely don't truly need them.


Some additional pieces of information that would be helpful in providing better assistance would be:

1. What is the volume of your display and sump?

2. Where is your sump located in relation to the display?

3. Are you pumping water through a particularly long piping ruin? Say greater than 8 ft?

4. Is your sump located on a different floor level than your display?

5. What equipment are you planning on running of the manifold?

6. What are the size of the bulkheads your going to use in the sump, return portion, and drain portion of your system?

7. How quiet does your equipment need to be?

8. Do you have a budget?. If so, can you tell us what it is?


This can be a pretty complicated or involved subject, and I'm happy to talk shop over the phone if that's easier. Just give me a ring if you want. Hope this helps, and let us know.

863-450-7092

 

[galantra]

1. What is the volume of your display and sump?

2. Where is your sump located in relation to the display?

3. Are you pumping water through a particularly long piping ruin? Say greater than 8 ft?

4. Is your sump located on a different floor level than your display?

5. What equipment are you planning on running of the manifold?

6. What are the size of the bulkheads your going to use in the sump, return portion, and drain portion of your system?

7. How quiet does your equipment need to be?

8. Do you have a budget?. If so, can you tell us what it is?

Thanks for that bit of information,
So regarding my system I am currently setting up a 150g cube with a custom 40 gallon sump. I plan on using a DC pump probably a EcoTech Vectra. I am going to house everything underneath the tank in the stand but would like a quiet system.


From pump to tank it would be about 6ft from sump to top return .( saying 7-8ft head pressure)

Standard marineland return and drain pipe which is rated around 700gph and plumb with schn 80 plumbing, possibly flex pvc for the drain.

Manifold I was hoping to add in to supply for possible reactors ( carbon, maybe zeo reactor ) and a way to drain the tank easier.

Main concern is back syphoning from the display tank. And no guarantee on what will be plumb just wanna be setup just in case

 

[theMeat]

Back siphon is easy. Drill a siphon break hole on top of supply line, just below water level.
Manifold looks cool but without a flow meter on each line it’s a guesstimate what each line is getting. And whenever you adjust one line/valve, the other lines are effected/changed as well

 

[naterealbig]

Thanks for that bit of information,
So regarding my system I am currently setting up a 150g cube with a custom 40 gallon sump. I plan on using a DC pump probably a EcoTech Vectra. I am going to house everything underneath the tank in the stand but would like a quiet system.

OK

From pump to tank it would be about 6ft from sump to top return .( saying 7-8ft head pressure)

Depending on your plumbing setup, the amount of head pressure could be significantly more. For reference, I use 2 x 1800 gph return pumps (3200 gph total), and without running any equipment right now, I am only getting 1200 gph to the display. Using my rule of thumb, (and assuming you are using the L1, and I am recalling the approximate (max) flow rate at 3100 gph, you will be left with ~ 1500 gph of usable flow. Assuming you want 5 x turnover (you could go as low as 2-3, or as high as 10) that leaves you with 750 gph to use for your manifold, which should handle the equipment you are talking about easily.

Standard marineland return and drain pipe which is rated around 700gph and plumb with schn 80 plumbing, possibly flex pvc for the drain.

If I remember correctly this setup has an overflow with a hole drilled for a 3/4" ABS bulkhead (return plumbing), and a 2nd hole drilled for a 1" bulkhead (drain plumbing). Have you run a tank with this setup before? If not, you may find that it is loud (think constantly flushing toilet) if you are running greater than 300-400 gph to the drain. Switching to a Herbie drain system may be beneficial, although not ideal if I am correct on the hole sizes inside of the overflow. Do some research on this and let me know what questions you have. If you are familiar with this setup, then disregard my comments .

Manifold I was hoping to add in to supply for possible reactors ( carbon, maybe zeo reactor ) and a way to drain the tank easier.

OK cool. Your manifold will not be helpful for draining the display tank. If you are thinking pulling out a few gallons from the sump for water changes, than this would be fine. Just remember you will be limited to the volume of the last chamber in your sump. Everything else looks good.

Main concern is back syphoning from the display tank. And no guarantee on what will be plumb just wanna be setup just in case

As @theMeat noted above, the back-siphon is pretty easy to solve. Another option is simply run a small portion of the return plumbing above the water line, and place the outlet of the return just below the waterline. This would allow for a minimal amount of back-shiphon - you will just need to test it to make sure your sump can absorb the volume that siphons back from the display. The benefit of this setup is, you don't have a small hole which will carry the chance (albeit small) getting clogged and causing an overflow situation.

 

[theMeat]

^ return line going up and over rim will do nothing to stop a siphon.

 

[naterealbig]

^ return line going up and over rim will do nothing to stop a siphon.

It certainly will, if you place the return outlet close to the surface. I have been using this method for siphon break for 15 years now without a failure. I'm happy to explain the fluid dynamics behind it, and/or send you a video of it in action on my current setup. Thank you for the feedback though.

[emoji4]

 

[galantra]

I’m gonna take photos, but my tank has a 3rd drill hole that originally I was going to use as a closed loop

So this a addition option for me as well

 

[galantra]

My real concern is trying to get away from using too many smaller pumps hence the manifold

The uncertainty of gph is my big concern. Even if I minus the water change option would I truly benefit adding one into my system? I like the whole idea and the ease of having one

 

[theMeat]

It certainly will, if you place the return outlet close to the surface. I have been using this method for siphon break for 15 years now without a failure. I'm happy to explain the fluid dynamics behind it, and/or send you a video of it in action on my current setup. Thank you for the feedback though.

[emoji4]

The return going up and over the rim has nothing to do with it. The return outlet being close to the surface does. Once enough water in tank siphons diwn to suck air into outlet the siphon will break. The problem is that return output/flow being that close to surface will likely cause splashing and noise

 

[naterealbig]

The return going up and over the rim has nothing to do with it. The return outlet being close to the surface does. Once enough water in tank siphons diwn to suck air into outlet the siphon will break. The problem is that return output/flow being that close to surface will likely cause splashing and noise

Well it's a good thing the two aren't mutually exclusive, and, that I mentioned in my post. And, you are absolutely wrong with regards to the only effect coming from the outlet being close to the surface. It can be true for smaller tanks, but as the volume of the display approaches infinity, there is no change in water level as the tank drains. So, without the small run of pipe being placed above the water line, you can drain a lot of water out of the display, even if it is not "technically" a siphon. I can also explain the fluid dynamics mathematically in this instance, or send you a video of the mechanism on my display.

While we are not talking about a tank with an infinite volume, we certainly could model this same phenomenon for any system that has a small enough ratio of sump: display volume.

Your solution works in some instances, and with some luck. The solution I'm suggesting (while requiring some forethought and planning) will work in all situations.

Be chatting.....

 

[theMeat]

Umm, yea ok. Water seeks it’s own level, then there’s gravity. If the end of the siphon is lower than the beginning it will continue to siphon until air breaks that siphon.
Do not wish to derail op’s thread, nor give bad advice, so that is that