[leebca]

The up-down motion for mixing salt into water prevents a vortex. A vortex just adds air to the water, which is undesirable. Also the vortex leaves salt in the center and it dissolves slower. Lastly the up-down motion for mixing prevents striation or any layering in the mixing container.

Aging takes time. You want to put a clean up crew in and feed them. The addition of simple, hardy lifeforms that require organic additions gets the aging process to move along. You want those 'other' bacteria to go through their blooms and reach a more or less steady state. You want all the small creatures, like pods to go through their blooms and die-offs too until they steady down.

The tank isn't aged as long as you see any:
cyanobacteria
diatom growth
red or slimy growths
hair or nuisance algae
brown 'algae'
etc.

Keep putting in food for the crew. I'm glad you're a reader. If you go to this post, you'll get some idea of the time sequence and where you are in the proposed time line for setting up a marine system: Starting up a Marine Aquarium. Find where you're at and then take the directions from there.