Thanks, no big deal that he added water clarifier but that is unneeded at this time. Here is a quick run down of how your tank will cycle.
1st-the water and conditioner need to be added with filters, by the way what filters are you using?
2nd-the water is going to start to turn a light milky color, probably around day 2-3, this is normal and ok. If you use cycle it will clear out much quicker. It is from the Nitrogen cycle happening. This is probably what your brother was trying to clarify but it will not help.
3rd-About 2-7 days later, depending on the use of Cycle, the tank will clear and do nothing. At this time have your water tested for Ammonia and Nitrates, local pet stores will do this for free. Once the water has tested good add a couple of feeder fish, they are hardy and cheep 0.12 each. This will start the waste, but more importantly bacteria to start building. If the feeders last 24-48 hrs add what ever fish you want. Make sure to float the fish for 15-20 min before adding and do not add the pet store water to your tank, some people diagree on this but I have contracted Ich twice from pet store water.
Finally-Have your water tested daily for the next week, if you start to see Ammonia or Nitrite (not nitrate) levels getting dangerous do a 25% water change. after that your tank is well on it's way and within a month will be established and not require much maintenence, depending on your end fish selection.