You do not need to overly mix the SW, since you have a small tank, take the Tropic Marine challenge, buy their salt and use their All-For-Reef for dosing, it easy to hand dose. The bucket of salt should last a year. I just mix in a container without a pump, let it sit for a day or two, then get a container and pick up the water and dump it back in the container, that easy. Bring the bucket in the house and heat the water and then check salinty. I have a Lagoon IM 25 EXT tank.