You need to get the basic test kits and test your water every couple days and let your ammonia, nitrites climb and when your trates go up and the others go down do a water change then you can slowly add stock, get ammonia, nitrite, nitrate and ph test kits for now and I recomend useing a refractometer instead on a swing arm salinity tester but if that is what you have then test it against a refractometer. You should have your water circulateing 30-50 times your total water volume with just PH's. I am sorry if it sounded like I was yelling when I asked you to slow down but this hobby is expensive enough without making mistakes and remember most all of the LFS's are in buisness to sell and make money so you should always research before buying anything. I dont really think you have messed things up bad, you might lose the snails and shrimp because they cant handle nitrates but if that is all you lose thats pretty good. I have setup several home tanks and setup 2 stores to carry SW stock and all are doing great. I understand how hard it is to let your tank sit there without any live stock in it for 8 weeks but trust me your tank will be in much better shape if you will do that the best looking tanks have gone up to 4 months with out adding any live stock. I feel you should let the tank cycle naturally and not use chemicals because almost every tank that I have seen that has tried to take shortcuts has ended up crashing at about the 8 month time so just let it all happen slowly and you will have a beautifull when it is done.