Pumping water from below the pump?

I have low profile reservoirs and was wondering today if I put an elbow on the intake of my submersible pump and put a pipe length pointing to the very bottom of my reservoir would the pump continue pumping water even if the water drops below the pumps original intake?

This might be a stupid question but I'd thought I'd ask before I go out and buy elbows to test it.

I just want to make sure that if the water level drops too low whilst I am away it can continue sucking water up from below.

I am restricted on space so I'm currently looking for a small water tank for me to store some
Extra water with a float valve

Think this might answer my question https://hevvypumps.com/blog/tech-talk/do-pumps-suck/21/68357

As long as water is in the pump the hose will be a low pressure zone and continue to pull water into the pump until the hose is below water level