Can you have too much pressure on your return line?

[Speedy77]

Hey guys!

I have an interesting tank setup going up in a few weeks and was looking for some advice on my return. With my current setup, I'll only be able to have a 1/2" return line on my 60g cube tank. I'm using a Fluval SP2 with it, which is rated at a max of just below 1000 gph, with a 1" output. If I reduce the output from 1" to 1/2", will I have any significant issues with my return? I'm using some flexible tubing and some barbed fittings, so this is where my main worry lies. I'll also be using clamps on these connections, so I'm not sure worried, but figured I'd ask to see what you guys think. Here's my entire return setup that I have planned:

Fluval SP2 Pump (strainer necessary or is uncovered ok?)
1" Barbed adapter
1" Vinyl tubing (clamped)
1" Barb x spigot adapter
1" Union
1" to 1/2" reducing bushing, slip x thread
1/2" Threaded male pipe adapter
1/2" Pipe
1/2" 45 degree elbow
1/2" pipe
1/2" Cepex ball valve (with unions)
1/2" pipe
1/2" Bulkhead
1/2" Pipe
1/2" 45 degree elbow (to avoid blocking strainer)
1/2" Pipe
1/2" 45 degree elbow (to avoid blocking strainer)
1/2" Pipe
1/2" 90 degree elbow
1/2" Bulkhead
1/2" Return nozzle
Into the Display

Let me know what you guys think. Thanks for reading!

 

[nervousmonkey]

yeah, you'll have reduced flow. @mcarroll can figure out the math and tell you how much loss you are going to have. It'll be a lot. It would be better to increase the size of the pipe back to 1" as often as you can; you lose a lot of pressure in the runs of pipe, fittings make a big difference but give your returns as much as you can.

 

[maroun.c]

Id go with a smaller pump. Dexreased pkumbing size usually results in increased pressure which van be annoying as it causes a jet of linear flow at the output. This might be fine in a larger tank but in a small ine itll likely hit some corals and itll ne difficult to manage.

 

[Seyoz]

yeah, you'll have reduced flow. @mcarroll can figure out the math and tell you how much loss you are going to have. It'll be a lot. It would be better to increase the size of the pipe back to 1" as often as you can; you lose a lot of pressure in the runs of pipe, fittings make a big difference but give your returns as much as you can.

If rated at 1" use two (1/2) returns plumbed.
While keep head pressure of 1" rating.
But I'd convert to two (3/4) returns.

 

[Seyoz]

Id go with a smaller pump. Dexreased pkumbing size usually results in increased pressure which van be annoying as it causes a jet of linear flow at the output. This might be fine in a larger tank but in a small ine itll likely hit some corals and itll ne difficult to manage.

With regards to this...
Could make manifold all (1/2)X3 returns for a 60, just include check valve before manifold..
That way can add ball valves each return..And Better overall control.

If (3/4) I'd only do two returns, both ball valves and check valve below splitting of return!

 

[Seyoz]

But wouldn't go smaller on pump...

 

[Seyoz]

If using hose from LFS, running behind tank not in water definetly use metal hose clamps...

 

[Seyoz]

If in hurry, use the hose and could plumbing and adjust exact design ..And later do the pvc...

 

[nervousmonkey]

If rated at 1" use two (1/2) returns plumbed.
While keep head pressure of 1" rating.
But I'd convert to two (3/4) returns.

I'm not sure what you mean by this.... The flowrate through two 1/2" pipes isn't the same as the flowrate through a 1" pipe. Fluid dynamics isn't linear like that. the formula for flow rate is: 1/4*pi*(pip diameter)squared*velocity of the fluid, so you get an effect that looks like this: flow rate for 1/2" pipe at a given velocity is 196 GPH and 1" pipe is 785 GPH, so it isn't additive.... Two 3/4 returns would give you about 800 GPH so not much more flow if you keep 3/4" pipe....

With regards to this...
Could make manifold all (1/2)X3 returns for a 60, just include check valve before manifold..
That way can add ball valves each return..And Better overall control.

If (3/4) I'd only do two returns, both ball valves and check valve below splitting of return!

Why put a ball valve on the return to slow it down, just open one up on the manifold that redirects back into the sump....

Change all of this to 1" from 1/2":
1" Union
1" to 1/2" reducing bushing, slip x thread
1/2" Threaded male pipe adapter
1/2" Pipe
1/2" 45 degree elbow
1/2" pipe
1/2" Cepex ball valve (with unions)
1/2" pipe
1/2" Bulkhead
1/2" Pipe
1/2" 45 degree elbow (to avoid blocking strainer)
1/2" Pipe
1/2" 45 degree elbow (to avoid blocking strainer)
1/2" Pipe
1/2" 90 degree elbow

 

[Seyoz]

I hear you but how many times have you designed PVC built it, then rebuilt it ten different ways and scientifically learned more?

 

[Seyoz]

I love un-traditional. Yes calculations are great, calculators are great from sites....And my graphing calculator from precalculus in 10th grade helps.

But, going off calculations. Designing and editing until happy with takes learning after calculations

 

[Seyoz]

But everyone's gonna cut, glue and adjust to their system, so if a snob walked up, pulled out his adding machine, but never cut PVC. I'd question talking over a forum

 

[Seyoz]

Too many other variables if not there helping on hand and foot.

 

[Seyoz]

It like describing use of manifolded piping, use of ball valves and check valve..

Think about resistance and flow.

If it's smaller diameter but has three exits into tank, not the same as just doubling diameter.

If just two returns I'd use (3/4")

 

[Seyoz]

Hey guys!

I have an interesting tank setup going up in a few weeks and was looking for some advice on my return. With my current setup, I'll only be able to have a 1/2" return line on my 60g cube tank. I'm using a Fluval SP2 with it, which is rated at a max of just below 1000 gph, with a 1" output. If I reduce the output from 1" to 1/2", will I have any significant issues with my return? I'm using some flexible tubing and some barbed fittings, so this is where my main worry lies. I'll also be using clamps on these connections, so I'm not sure worried, but figured I'd ask to see what you guys think. Here's my entire return setup that I have planned:

Fluval SP2 Pump (strainer necessary or is uncovered ok?)
1" Barbed adapter
1" Vinyl tubing (clamped)
1" Barb x spigot adapter
1" Union
1" to 1/2" reducing bushing, slip x thread
1/2" Threaded male pipe adapter
1/2" Pipe
1/2" 45 degree elbow
1/2" pipe
1/2" Cepex ball valve (with unions)
1/2" pipe
1/2" Bulkhead
1/2" Pipe
1/2" 45 degree elbow (to avoid blocking strainer)
1/2" Pipe
1/2" 45 degree elbow (to avoid blocking strainer)
1/2" Pipe
1/2" 90 degree elbow
1/2" Bulkhead
1/2" Return nozzle
Into the Display

Let me know what you guys think. Thanks for reading!

To Einstein: Not Speedy
Back to Beginning: it's a canister no way with head pressure exactly 1000gph, after use at Max would go 900.

Now Speedy,
It's a canister, a pressurized unit... They rate lower as used..As fill with bacteria and slime naturally restricts flow through devices lowering headpressure as internal sponge slowly clogs. I also understand the harder you make the internal pump work, the quicker gonna burn out or have problems. The slower it goes the warmer contact water also gets!

 

[Seyoz]

If it was a pump and a sump would go with Equation.

But Canister, don't have same head pressure because varies over use.
Head pressure from a sump based return pump don't drop over use, once plumbed set. Can adjust with ball valves.

 

[nervousmonkey]

I agree with you man, you have to actually create and put together something some time before you can be a critic. And I always take my first attempt apart. LOL Good call on that one.

I am just saying that science is still science and that a specific diameter pipe will only want to push so much water through it. But you are right, put a big pump on the thing and you can increase the velocity of the water, decreasing the pressure in the pipes, so it makes sense what you are doing, it really does. It's just not what I would do, but we all are different for very good reasons. Now I see how you are doing your plumbing and it's smart as hell, never thought of doing that before. May try it on a smaller tank set up to see what happens. Thanks man!

To Einstein: Not Speedy
Back to Beginning: it's a canister no way with head pressure exactly 1000gph, after use at Max would go 900.

Now Speedy,
It's a canister, a pressurized unit... They rate lower as used..As fill with bacteria and slime naturally restricts flow through devices lowering headpressure as internal sponge slowly clogs. I also understand the harder you make the internal pump work, the quicker gonna burn out or have problems. The slower it goes the warmer contact water also gets!

I understand what you're saying Mr. Newton, of course it won't stay at 1000, but I was pointing out the numbers an

To Einstein: Not Speedy
Back to Beginning: it's a canister no way with head pressure exactly 1000gph, after use at Max would go 900.

Now Speedy,
It's a canister, a pressurized unit... They rate lower as used..As fill with bacteria and slime naturally restricts flow through devices lowering headpressure as internal sponge slowly clogs. I also understand the harder you make the internal pump work, the quicker gonna burn out or have problems. The slower it goes the warmer contact water also gets!

What's a canister? The Fluval SP2? I'm just not following you man.

 

[Seyoz]

I appreciate all the thought on this thread, for the Group.

 

[Seyoz]

Type: Brand:
Hob hang on back. Aqua Clear.
Canister. Fluval

 

[nervousmonkey]

type google.com and the Fluval SP2 and *this* is what you get: Google search
It is not a canister, it's a regular ol return pump