If your Saltwater is sitting in a tank always have a small pump in it to constantly mix it. Always check the temperature to make sure its the same as your tank.. i know i have to make 70 gallon water changes for my tank Every month. and here in Florida my garage gets really hot and i have to wait for the water to cool down, before adding it to my tank.. if its to cold put a heater in it.If you have specks in the water after the tank is empty you can wash it out with vinegar and water and rinse it out really good I do that everytime before making a fresh batch. If you buy a RODI system it will pay for its self in time to make your own salt water .check out bulk reef supply they have videos about anything you want to learn.being so much has changed in reefing last few years.. check out the newer videos from 2021. There is alot of info there.also they are also on utube. Saltwater aquarium also has good videos and reef dudes... & BSRtv investigates check them out. Lots of info from the pros.I added a little salt water today, but not a lot because I needed to check my hydrometer for accuracy first, which I did when I went to the LFS. I’ll add more though. I don’t mix my own salt water, I buy it but one of the places I bought it from has a lot of little specks floating in the water. I thought it might be salt, but it’s been sitting a while. After I put it in my tank, I noticed how much extra stuff I had floating. Idk what it is. I showed someone at a different LFS and he said he doesn’t know either, but he also told me to put bleach in my tank lol so I’m not taking his word. But i can add salt water then top off with RO DI, that’s right? How do I know how much RO DI to top off with?