Your live rock looks god and will certainly help with the cycle. What's your future plans for this tank? Fish only or reef? Only reason I ask is if it is going to be a reef I would recommend starting with fresh water and fresh sand too if that was from the old set up. The bb in fresh is different to salt. Tap water is no good long term for a reef tank and if this water was previously used to house freshwater fish I can only assume its from a tap. Doing things right the first time will save you a hell of a lot of time and money in the future. Ro-di water is best for salt
you may also need a powerhead and some salt water test kits as well as a refractometer for salinity (hydrometers are ok but not as accurate) Cycle the tank using a raw shrimp and test for amm until you see a spike (good cycle is 4ppm) then you will see nitrites and then finally high nitrates. Should take between 2-4 weeks. Any other questions just ask!