Hey Pass ..
Your right on .. there are lots of brands of salt mix, I happen to use “Instant Ocean” (see
http://www.drsfostersmith.com/Produc...e-_-Salt_Mixes)
Basically you need to mix your water but you need to do it correctly you need to get some sort of device to measure how much salt is in the water so you know if your using too much or too little (also when mixing new water for water changes you can match the old water as not to stress the fish)
The person whom told you to get a large water bucket was right .. if your not filtering your water (which you will want to do some day) you will need to de-toxify the water first (see Amquel
http://www.drsfostersmith.com/Produc...N=2004+112994). You need to remove harmful chemicals to the fish .. mix in your salt and get it to a salinity of like 1.025-1.026 – the cheapest way to measure this is with a hydrometer (
http://www.drsfostersmith.com/Produc...N=2004+113761).
There are better ways of doing this (using filtered water, a refractometer) but this is an expensive hobby and you may want to take it slow .. a 75 gallon is a big one to start with and I would recommend lots of internet reading.
Looking forward -
You need to plan out your filtration and where your going to put all the different items (Heaters, Skimmers, etc) you need. Have you done any research on a sump or a wet/dry filter?
Cheers