(repost) Help with closed loop ...

[Joe V.]

(NOTE: I posted this on rec.aquaria.tech, but this group seems much more
alive!)

I attempted to build a closed loop system based on Marc's directions
(http://www.sparklingfloorservice.com/tank/closedloop.html).

The deviations I took are as follows:

- Using a Eheim 1250 pump instead of a Mag 5

- return from pump to SCWD is flexible hose (not PVC). This was due to the
return hole that was available in my tank cover ...

- my SCWD is lying on flat, not vertical like Marc's.

I used PVC cement where I could, and took effort to make everything
air-tight. However, no matter what I do, after some time I get micro-bubbles
.... whenever this happens, I can see the air bubble through the flexible
pipe so I think it has to do with the pump sucking water from the tank.

Is the Eheim 1250 not a good substitute for the Mag? Is it because I'm
trying to suck the water out, but the run is too long? I have similar
dimensions from the intake tube to the pump ...

Or, is it because the SCWD is on it's side? I read the instructions and I
thought it didn't matter ... however, not sure if I'm imagining this but I
think I hear the SCWD's internal gears and am afraid I'm putting too much
strain.

The other thing I was thinking was that my seals are really not tight, and I
should re-do the whole contraption ...

Any help would be appreciated.

[Marc Levenson]

Joe,

What I always recommend when the problem arises is to unplug the pump for 10
seconds and then start it up again.

It could be that your flexible tubing is too small, and it is causing cavitation
in the pump which literally creates new airbubbles.

How far submerged is the intake line that leads TO the pump? If it can get any
air at all, it will add to this problem.

Marc


"Joe V." wrote:

> (NOTE: I posted this on rec.aquaria.tech, but this group seems much more
> alive!)
>
> I attempted to build a closed loop system based on Marc's directions
> (http://www.sparklingfloorservice.com/tank/closedloop.html).
>
> The deviations I took are as follows:
>
> - Using a Eheim 1250 pump instead of a Mag 5
>
> - return from pump to SCWD is flexible hose (not PVC). This was due to the
> return hole that was available in my tank cover ...
>
> - my SCWD is lying on flat, not vertical like Marc's.
>
> I used PVC cement where I could, and took effort to make everything
> air-tight. However, no matter what I do, after some time I get micro-bubbles
> ... whenever this happens, I can see the air bubble through the flexible
> pipe so I think it has to do with the pump sucking water from the tank.
>
> Is the Eheim 1250 not a good substitute for the Mag? Is it because I'm
> trying to suck the water out, but the run is too long? I have similar
> dimensions from the intake tube to the pump ...
>
> Or, is it because the SCWD is on it's side? I read the instructions and I
> thought it didn't matter ... however, not sure if I'm imagining this but I
> think I hear the SCWD's internal gears and am afraid I'm putting too much
> strain.
>
> The other thing I was thinking was that my seals are really not tight, and I
> should re-do the whole contraption ...
>
> Any help would be appreciated.

--
Personal Page: http://www.sparklingfloorservice.com/oanda/index.html
Business Page: http://www.sparklingfloorservice.com
Marine Hobbyist: http://www.melevsreef.com

[Joe Varghese]

Marc Levenson > wrote in message >...
> Joe,
>
> What I always recommend when the problem arises is to unplug the pump for 10
> seconds and then start it up again.
>
> It could be that your flexible tubing is too small, and it is causing cavitation
> in the pump which literally creates new airbubbles.
>
> How far submerged is the intake line that leads TO the pump? If it can get any
> air at all, it will add to this problem.
>
> Marc
>

Thanks Marc! I was hoping you'd answer :)

The intake is submerged about 6" ... I didn't drill holes or anything
as you have, though (essentially a tube going in with a net covering
the intake opening). Could this be a reason?

The height differential between the end of the intake and the pump (on
the outside) is about a foot.

[Marc Levenson]

I'm guessing it is a restriction issue. If you were using larger pipe, flow would be
increased. For example, the Mag 5 (and 7) have a 1/2" outlet, but the instructions state to
double that for plumbing.

You may just have to build it exactly like mine. :P

Marc


Joe Varghese wrote:

> Marc Levenson > wrote in message >...
> > Joe,
> >
> > What I always recommend when the problem arises is to unplug the pump for 10
> > seconds and then start it up again.
> >
> > It could be that your flexible tubing is too small, and it is causing cavitation
> > in the pump which literally creates new airbubbles.
> >
> > How far submerged is the intake line that leads TO the pump? If it can get any
> > air at all, it will add to this problem.
> >
> > Marc
> >
>
> Thanks Marc! I was hoping you'd answer :)
>
> The intake is submerged about 6" ... I didn't drill holes or anything
> as you have, though (essentially a tube going in with a net covering
> the intake opening). Could this be a reason?
>
> The height differential between the end of the intake and the pump (on
> the outside) is about a foot.

--
Personal Page: http://www.sparklingfloorservice.com/oanda/index.html
Business Page: http://www.sparklingfloorservice.com
Marine Hobbyist: http://www.melevsreef.com

[Joe V.]

The restriction issue between the pump and the return piping (i.e., in my
case the flexible tubing)? Or, do you think the restriction is in the
intake?

Thanks, King ;)

joe

"Marc Levenson" > wrote in message
...
> I'm guessing it is a restriction issue. If you were using larger pipe,
flow would be
> increased. For example, the Mag 5 (and 7) have a 1/2" outlet, but the
instructions state to
> double that for plumbing.
>
> You may just have to build it exactly like mine. :P

[Marc Levenson]

What size is your flexible tubing?

Marc

"Joe V." wrote:

> The restriction issue between the pump and the return piping (i.e., in my
> case the flexible tubing)? Or, do you think the restriction is in the
> intake?
>
> Thanks, King ;)
>
> joe
>
> "Marc Levenson" > wrote in message
> ...
> > I'm guessing it is a restriction issue. If you were using larger pipe,
> flow would be
> > increased. For example, the Mag 5 (and 7) have a 1/2" outlet, but the
> instructions state to
> > double that for plumbing.
> >
> > You may just have to build it exactly like mine. :P

--
Personal Page: http://www.sparklingfloorservice.com/oanda/index.html
Business Page: http://www.sparklingfloorservice.com
Marine Hobbyist: http://www.melevsreef.com