Running External Pump Below Sump – Bad Idea?

[samuelgrant]

I'm wondering if it's a bad idea to have the intake to an external return pump plumbed into the bottom of the sump, rather than into the side? Here's what I'm thinking:

orange is the return line, purple is the pump, blue is overflow from DT

Would that have any adverse effects on the pump? Would it change the back siphon when the pump is turned off, if the water has to flow uphill a bit to get back into the sump? Are there any other issues you could foresee with this setup?

Asking because I'm trying to save horizontal space in my stand, but I have some vertical space to play with, thought this might be a good solution. And apologies if this question has been asked, couldn't find anything like it in the forum search.

Thanks for your wisdom!

 

[Chuk]

I don’t see a major problem with it. Just make sure you have a way to isolate the pump from the tank otherwise every time you have to do maintenance on the tank you have to drain the whole sump. It’s actually better in some cases because it makes sure you have a flooded pump suction.
It won’t change how the tank drains when the pump stops, it will still drain to the pipe level when the pump shuts off.
I’m sure it’s just a drawing thing but if you plumb your display to the sump that way every time flow stops the whole display will drain to the sump and you’ll flood so make sure you have an overflow weir or bring the pipes to where you want the water level at the top.

 

[samuelgrant]

Thanks for the wisdom! After a bit more thinking, I've decided to go with a different plumbing setup, but it's good to know this is an option for the future.
And yeah, I wouldn't want to plumb an overflow like in the picture lol, I was just too lazy to draw the pipes full height.