Welcome to the SW
1. Get your salinity where you want it (1.020 is not too low, usually where most LFS
keep theirs, but it does semm to have an adverse effect on some of your hitch hikers)), adding salt directly to the tank when you have livestock is not the best route as it can be very caustic. I premix all of my SW
2. To start a cycle, you will need an ammonia source. I prefer 1 raw, unseasoned jumbo shrimp per 30G from my gorcery store.
3. Get a liquid test kit. API Salt Water test kit is a good starter kit.
4. Get a refractometer.
5. You can start adding livestock once your ammonia/nitrItes spike and hit 0 then do a PWC
to get your nitrAtes down and you can slowly add livestock.
6. The sediment is probably dust from the sand or the filter media, you can leave it and get it when you do your PWC