Question about Sumps and Overflows

For me and I know for many others the biggest concern of a sump is overflowing. I have never yet ran a sump however I would LOVE to, if i knew for certain I would never have an overflow. One thing I was thinking about while spending countless hours reading threads is:

Hypothetically say your system was running fine, then all of the sudden your overflow stopped siphoning (regardless of running a DIY PVC overflow/Eshopps or other Overflow Boxes) your return pump would eventually pump a lot of water back into your display causing an overflow.

However, it seems as though a simple solution to this would be to have your return pump intake sitting near the water level in your return area of your sump. That way it could only possible pump a minimal amount of water back to your display....

Seems to me a pump running dry > a possible overflow....

Let me know if my logic is bad in this

 

It can happen and has happend to me when doing maint on the system and I accidentally did something to stop the syphon (like pour water into the overflow causing too much air). It has never stopped while I was not there working on it, such as by debris / large snail. Use a very porous sponge as a prefilter keeps inhabitants out.I have used this set up since 2004 without issues.

 

Danger, I'm also afraid of causing my overflow to stop siphoning, but I don't understand how it happened (I was still making my DIY and the tubes came apart and lost pressure)

Not sure how else the siphon would stop on its own, mine has been running for almost a week brand new and no problems

However that is a huge concern I have about this DIY overflow, also another concern would be my return line from the sump to the DT becomes disconnected, then you'd have your entire sump and most of your DT drain out.

I'd rather have my pump burn out than vacuuming salt water

 

Maybe you should glue the tubes and use the screw unions for tubes that you will want to seperate in order to clean in hte future. You wouldnt have most of your DT drain out as long as your drain intake is close to the surface of the water, that way the only amount to drain out would be a couple inches AT MOST of your display tank which to my understanding you should calculate and pre-test to see if your sump can handle it.