Tried to test out a redstone water elevator, think it may work when all is good.
Used pistons to switch between magma block and soul sand (normal pistons pushing blocks back and forth), works fine to get the downwards suction of the magma blocks to change to the upwards stream from the soul sand.
But when changing from soul sand to the magma block, it is still pushing those bubbles and me straight up.

Second issue, related to this build project.
Its ok if were supposed to have a water block next to the magma block and soul sand water streams, but shouldn't it update the stream when you open up?

ex: i had 15 waterblocks in hight and 3 x1 width, blocked off middle row from 3'rd from bottom to the top.
Bubbles was on the bottom two waterblocks, but not above.
Removed the blocks on the middle row (raplased them with water sourse blocks)
and still there was only bubbles on the bottom two blocks.

hope this helps