Can one pump be both closed loop and return?

[jafoca]

Hey,

I was just thinking about the new nano set up I want to put together and i had an interesting thought... I was wondering if it is possible for one pump (in my case I want to use a external little giant pump rated at 770 gph) for both a sump return and a closed loop.


Is this sort of thing possible with a bit of creative plumbing?


I was thinking one overflow into sump, one overflow into pump with outflow from sump t'd into this line, gate valve between sump and pump, and then 4 return lines out from the pump back to the display.

good or unable to balance the flow? Is this a flood waiting to happen? a balancing nightmare?

 

[albinooscar]

A pump used for sump return by definition is not a closed loop.

So the answer is no.

You could split the return and direct it in 2 different directions.

 

[jafoca]

um right...

You response is not helpful at all, just critical of my use of the term "closed loop" Ok, fine...


Is it possible to create a hybrid system which is half sump return half closed loop running off of one pump? A "Partially-Closed loop" if you will?

 

[kgross]

2 big problems, first if you have an overflow into the pump you will be getting bubbles into the pump so you will get lots of micro bubbles in the tank. Second if you do not use an overflow if your pump stops for any reason your tank will drain into your sump and oveflow.

Basicly you can not do a closed loop and return pump out of the same pump.

What I would suggest is a small pump for your return and then just use the LG as a closed loop.

Kim

 

[shadofax69]

Nope by definition a closed loop is an intake in the aquarium and the outputs in the aquarium. If you have a pump returning water from the sump to the tank it is just going to be a main return pump no matter how you plumb it. There is no possible way to seperate the two components to make what you have a "hybrid"

 

[MayoBoy]

It should be possible (at least in theory - but it's early and my theories don't always work in the light of day...)

You would have an overflow to the sump and a split suction (like on a swimming pool with skimmers and main drain). One suction from the sump, the other from the tank (It would have to be a direct suction - not from an overflow). The main problem would be balancing the sump suction. It would require you to valve the suction lines which is never a good thing.

However, the pump is probably way undersized for that. 770 is just about right for a 600 gph overflow (with head loss, etc). May as well dedicate one for the sump, and a second for a closed loop. (or just do a MaxiStream mod)

I'll think on in some more and see what holes can be poked into it.

 

[jafoca]

my thoughts exactly mayoboy...

One of the above posters (the only one that had a useful response) said the thing stoping the hybrid system from working was the fact that if power was lost all water from the tank would backflow the closed loop, overflowing the sump... If this obsticle can be overcome, however, maybe there is a possibility here.

As of right now I am planning to use two pumps, but still interesting, no?

 

[MayoBoy]

That's simple enough to overcome with a checkvalve on the sump suction line. It would need to be cleaned occasionally but that's easy enough to do.

I'm not a fan of single, do everything pumps systems. If the pump fails, you're completely out of luck. I'd rather have a pump dedicated for each purpose. That way, if one fails (at 9:00 on Christmas Eve usually), you still have some circulation/filtration.

 

[M. Python]

Give up, it canââ"šÂ¬Ã¢"žÂ¢t be done. For one thing your sump to tank will have a lot of head pressure and a closed loop will have almost none. That is one of the problems, the other thing is what you want to do would be the same as having one return in the beginning of the sump and another at the return end of the sump not a closed loop even if you put in a t at the intake of the pump itââ"šÂ¬Ã¢"žÂ¢s a waste of time, itââ"šÂ¬Ã¢"žÂ¢s not a closed loop. You can only do it with two pumps. Closed loops are more efficient then the same sized pump pumping water up to the tank from the sump.

 

[RichConley]

<a href=showthread.php?s=&postid=7331159#post7331159 target=_blank>Originally posted</a> by MayoBoy
That's simple enough to overcome with a checkvalve on the sump suction line. It would need to be cleaned occasionally but that's easy enough to do.

Checkvalves exposed to salt water WILL fail, in relatively short order, no matter how much you clean them.


I dont really see the point in this. What does it gain over a return pump to a multiple outlet manifold.

 

[albinooscar]

<a href=showthread.php?s=&postid=7329305#post7329305 target=_blank>Originally posted</a> by jafoca

You response is not helpful at all, just critical of my use of the term "closed loop" Ok, fine...

Ouch! That hurt especially that I was not trying to be critical just short and to the point. Ok, fine....

Ron

 

[albinooscar]

<a href=showthread.php?s=&postid=7331407#post7331407 target=_blank>Originally posted</a> by RichConley
I dont really see the point in this. What does it gain over a return pump to a multiple outlet manifold.

Thanks RichConley! That's what I was wondering and also suggested but got slapped down.

Without critiquing, where would this world be? Not that I was.

Ron

 

[MayoBoy]

<a href=showthread.php?s=&postid=7331407#post7331407 target=_blank>Originally posted</a> by RichConley
Checkvalves exposed to salt water WILL fail, in relatively short order, no matter how much you clean them.

I'm afraid will have to agree to disagree on that point. There are plenty of quality check valves that work and have been working. But they have to be maintained or they'll fill up with crud and leak.

 

[douggiestyle]

the only thing that differentiates a closed loop system from anything else is the very fact that its closed. ron gave a good answer and a good suggestion though its presumptive on what your possible motive is with such a request.

what it sounds like (and im not a mind reader) you would like jafoca is high flow using one pump but not having all that flow running through the sump. am i correct?

 

[sr71pav]

Could you sketch a picture of what you're talking about for this hybrid system? I just can't picture in my head how the CL isn't just another drain to the sump.

 

[douggiestyle]

a check valve in the sump output would only stop a low return line inside the tank. which could more easily be addressed with a siphon break.

 

[MayoBoy]

The check valve would be on the sump suction line. It would stop the suction line in the tank from backsiphoning into the sump in the event of a power failure.

 

[RichConley]

<a href=showthread.php?s=&postid=7331617#post7331617 target=_blank>Originally posted</a> by MayoBoy
I'm afraid will have to agree to disagree on that point. There are plenty of quality check valves that work and have been working. But they have to be maintained or they'll fill up with crud and leak.

THe problem with check valves is that 99% of the time, they are open. While they are open, you are getting calcification on the seal. you are also having stominiferans, coral planulae, feather dusters, etc all settling out on that seal. So when you lose power, that seal can not completely close. No, its not going to flood your house in 30 seconds, but give it a couple hours with no power, and you have failure.

The fact of the matter is, check valves are not designed to absolutely stop water from flowing that way. Theyre designed to prevent heavy backflow.



Now where the 'semi-closed loop' comes into play, and becomes interesting, is skimmers. Think of this, you've got a large recirculating pump on a skimmer. It is being fed from a T, one side going into the skimmer, and pulling water (recirc), and the other side is a drain fed line. That way new dirty water is instantly exposed to bubbles as it goes through the pump (the major advantage of non-recirc skimmers), but has that long contact time of recircs.

 

[douggiestyle]

<a href=showthread.php?s=&postid=7331713#post7331713 target=_blank>Originally posted</a> by MayoBoy
The check valve would be on the sump suction line. It would stop the suction line in the tank from backsiphoning into the sump in the event of a power failure.

imposible if im understanding you correctly.

 

[cres]

Two concerns:

1) Your check valve would be critical in this setup. Maintenance would be very important.

2) You would have to restrict the "closed loop" feed to the pump. Because this line has head pressure to the pump, it would feed the pump while likely keeping the check valve closed. You would have to draw harder than the "closed loop" could feed to open the check valve and draw water from the sump. The pump would therefore be working a little harder, therefore, you would need to upsize the pump to balance this.