How do I plumb two systems together?

[seaguy7]

I just finished building a frag/QT tank. It is about 35 gallons. I want to add a sump to this tank and allow me to isolate it from my main display system for use as QT or when nothing is in QT, plumb them together so both systems benefit from the increased water volume and lower maintenance.

My problem is I canââ"šÂ¬Ã¢"žÂ¢t figure out how to plump them together. Perhaps I am being dense, but basically the frag sump is going to be smaller and therefore lower than my main sump. My question is, how can I plumb my display tank/sump together with my frag tank/sump?

The water level of the main sump will be higher than the frag sump so I canââ"šÂ¬Ã¢"žÂ¢t gravity flow it from the smaller sump to the larger sump and I donââ"šÂ¬Ã¢"žÂ¢t think I want overflow from the main sump to the smaller sump, since this then means my smaller sump is where the water level will change due to evaporation and given it's small size relative to the whole system, it would evaporate too quickly. I already have an autofill on my main sump.

Am I making sense? Am I missing something? Is there an easy way to do this?

Hereââ"šÂ¬Ã¢"žÂ¢s a drawing of the two systems.

 

[kevin gu3]

You will need to connect the sumps thru a valved line. If the QT sump's top edge is not as high as the main sump's top it will overflow first in a power failure. If the bottom is not as low as the main sump's it will run dry first. So you need the sumps of the same height at the same level. For example if the main sump is on the floor and 2 feet tall, the QT sump needs to be on the floor and 2 feet tall.

Run the QT tank's output to a tee with legs to both sumps. Put a ball valve on both legs. Then run a separate valved line that connects the sumps thru bulkheads.

By adjusting the tee valves you can have all/some/none of the QT outflow going to the main sump and then to the QT sump by way of the separate line. The QT sump will normally have a lower water level than the main (unless power failure or you close all the valves).

 

[seaguy7]

<a href=showthread.php?s=&postid=7465804#post7465804 target=_blank>Originally posted</a> by kevin gu3
You will need to connect the sumps thru a valved line. If the QT sump's top edge is not as high as the main sump's top it will overflow first in a power failure. If the bottom is not as low as the main sump's it will run dry first. So you need the sumps of the same height at the same level. For example if the main sump is on the floor and 2 feet tall, the QT sump needs to be on the floor and 2 feet tall.

Run the QT tank's output to a tee with legs to both sumps. Put a ball valve on both legs. Then run a separate valved line that connects the sumps thru bulkheads.

By adjusting the tee valves you can have all/some/none of the QT outflow going to the main sump and then to the QT sump by way of the separate line. The QT sump will normally have a lower water level than the main (unless power failure or you close all the valves).

OK, thanks for the info. That makes sense. I wasn't planning on making the QT sump as tall as the main sump but I guess I have no choice. I haven't made the QT sump yet so I can still do that.

-Greg