Tank 2.0 RUGF/Pressure system

[CHOMPERS]

Someday I'll get around to doing that math for you. I don't like doing math with a headache or when I'm tired, so we're looking at the end of spring or mid-summer.

As far as a stress fracture, is that likely in acrylic ?

Nope. As long as you are 1.5 diameters away from the next hole or one diameter from an edge, there isn't a stress riser.

but those pumps will lose substantial flow by having to push thru the canisters, then up thru all that PVC with 240G of water pushing back down on it. Again, I imagine it would work but I think you should expect the pumps to flow like there's 9' or 10' of head.

Nope. The only issue is when the canisters are dirty. In a closed loop system, it is zero head. The pvc restriction is insignificant.

I was careful to size the drain to provide gravity powered GPH in excess of the pump capacity so as to maximize the potential of the pump.

In a closed loop, gravity doesn't apply. You don't have to oversize the drain side. You can use the size that is on the pump or a size larger.

If the return pipe/RUGF is sized to adequately flow the capacity of the pump(s) would I not still calculate maximum head pressure as the vertical distance between the outlet of the pump and the surface of the water in the tank ? What am I missing ?

Again, the simple answer is that it is a closed loop. You don't have to worry about it.

For open loop systems, yes it is only the vertical distance.

Head pressure stated by the mfr. will be straight pipe with no obstructions. You plan to put some serious obstructions in the way of that pump.

Not really. It is perceived that way because there is a lot of stuff there. Designed well, Chris will have a good running system.

...but if you're adding under gravel returns I would expect your actual head pressure to be significantly higher...

The RUGF system will have very little restriction at all. Again, attention to details during the design phase is what determines success and failure. The surface area of the gravel bed is large enough so that any restriction is negligible.

The chart for your pump lists head height, not head pressure.

Actually, if you wanted to split hairs, "head" and "pressure" don't belong together. Head is measured in vertical feet and pressure is measured in pounds per square inch. You can use either head or pressure to talk about performance lost from various restrictions, but not both in the same discussion. It is about the equivalent of doing math with metric and English units without doing the conversions. I hope that makes sense.

...then it's time to shoot the engineer.

 

[JakeH]

No pump loss with a closed loop?! See, I learn something new every day! Good luck OP! Cant wait to see the final product!

 

[dawnmarie]

What concerns you about sumps and power outages?

That was poorly put wasn't it. The two concerns aren't neccessarily related.

Also, have you had any experience with Sequence pumps or Aqua UV filters?

I have not owned either brand. I have previous experience with Little Giant in non aquarium applications in my business. Once I find a good product I tend to stick with it(old and set in my ways). The Ocean Clear's were a windfall. I probabaly lean away from a sump and towards a closed system due to my background building, operating and maintaining a Non-community water system as part of my job. I am comfortable with pressure systems and servicable cartridges.

 

[dawnmarie]

Hi, Chompers
Thanks for the feedback.
I feel like I'm about to step on Superman's cape but I'm hoping you can clarify something for me/us . Keep in mind that I am not contradicting you, rather, I am offering my perception of the concept(Right or Wrong).

Originally Posted by dawnmarie
I was careful to size the drain to provide gravity powered GPH in excess of the pump capacity so as to maximize the potential of the pump.

In a closed loop, gravity doesn't apply. You don't have to oversize the drain side. You can use the size that is on the pump or a size larger.

I designed the drain system to still be functional should I ever feel the need to go with a sump.
I think your quote is absolutely correct taken at face value, however, I am guilty of calling it a closed loop when technically it is not. I may be splitting hairs but a closed loop as the name implies is an uninterrupted circuit or loop from the inlet to the outlet of the pump.There is a break in the loop in this setup, the aquarium itself.
I tend to agree with you that the RUGF(I 'm intentionally leaving the filters out of this discussion ) shouldn't significantly affect the output of the pump. I do think the design of the suction side /drain can effect the output of the pump. If I gravity feed water in excess of the pumps capability to the inlet of the pump, then any excess supply will create positive pressure at the inlet. This pressure will be small but any positive pressure at the inlet of a pump will increase it's performance. My thought is, the small increase in pump performance will be offset by the small loss in output caused by parasitic losses. I may be wrong but with clean filters I expect to see flow numbers close to 85% of the pumps rating or 1800 GPH. I will do a better job of documenting and photographing this project and share it with you all.

 

[CHOMPERS]

old and set in my ways

You are only six years older than me. Who are you calling old?



I have to run, but a short answer on the next post is gravity pushes down on both sides of the "loop", so it cancels out. It is a basic physics principal. In work or potential energy equations, you end up where you started so the effects of gravity don't apply.

Imagine an equation like this:
drain side flow with effects of gravity = return side flow with effects of gravity

You can subtract/cancel the effects of gravity from both sides.
You will be left with
drain side flow = return side flow

 

[tcarswell]

Sorry Chris but Chompers amazes me with every post lol. I couldn't begin to improve on a system he has approved or been a part of Maybe someday. It looks fantastic and in fact I have learned a lot here thanks guys !

 

[dawnmarie]

You are only six years older than me. Who are you calling old?

If I thought I would make it this long I would have taken better care of myself.

My thought is, the small increase in pump performance will be offset by the small loss in output caused by parasitic losses.

OR

Imagine an equation like this:
drain side flow with effects of gravity = return side flow with effects of gravity

I think we just said the same thing. The difference is an academic and an Okie engineer. In case anyone missed it ,I'm the Okie(Yes , my relatives came from Oklahoma and Missouri.)
Thanks, Chompers

 

[dawnmarie]

Sorry Chris but Chompers amazes me with every post lol.

Me to, but I gotta keep trying, It's in my nature. once a Hotrodder, always a Hotrodder

 

[CHOMPERS]

I feel like I'm about to step on Superman's cape

I step on it more than anyone else.

I designed the drain system to still be functional should I ever feel the need to go with a sump.

That makes sense. There is never any harm in going bigger.

I think your quote is absolutely correct taken at face value, however, I am guilty of calling it a closed loop when technically it is not. I may be splitting hairs but a closed loop as the name implies is an uninterrupted circuit or loop from the inlet to the outlet of the pump.There is a break in the loop in this setup, the aquarium itself.

If you were to imagine connecting the inlet and outlets in the aquarium with a short piece of hose, that would make it a closed loop, right? If the same piece of hose were laying on the bottom of the tank not connected to anything, it wouldn't have any affect by itself, right? The hose won't pump by itself and can be assumed for all practical purposes to be frictionless. With the hose in place or laying on the bottom, there won't be any difference in the performance of the pump. You could also say that if the hose were there in the aquarium connecting the inlet and outlet, and that if the hose just magically dissappeared, the performance would remain the same. Right? That's why it qualifies as a closed loop. The aquarium completes the loop.

On the other hand, a sump is not a closed loop. The drain side flow is equal to the return side flow when it is running, but the two sides are still independent. When you shut off the pump, the return side stops but the drain side keeps going. In a closed loop, the two sides are not independent. When one side stops, the other does too. Both sides mirror each other and never deviate.

I do think the design of the suction side /drain can effect the output of the pump.

The suction side is the weakest link and you are thinking along the right lines. However, water is not compressible/expandable for our purposes. In a closed loop, this property causes the suction side to act (mathamatically and dynamically) like the pressure side. The pump actually pulls on the water. That's why it isn't necessary to oversize the drain side in a closed loop.

In an open loop/sump the pump can not pull on the drain side water so the plumbing must be sized to rely on gravity.

I gravity feed water in excess of the pumps capability to the inlet of the pump, then any excess supply will create positive pressure at the inlet.

You've almost created a perpetual motion machine. Keep in mind that gravity is also pushing equally on the pressure side plumbing and in the opposite direction. It cancels out the effect of gravity on the suction side.

A helpful tool in fluid dynamics is that a dynamic system should be able to be represented statically. If not, it probably won't work. It also makes it exponentially easier to grasp all of the concepts happening at the same time.

 

[CHOMPERS]

an Okie engineer. In case anyone missed it ,I'm the Okie

I'm a card carrying afro engineer.