LOL. I love a good debate. You say its only 4mths old with all that stock and tap water source. Not sure what you use for flow but i would bet its not enough. I will leave some links that im sure you wont read but i would save them. Also whene you crash or come very close pls come back and post those pics.
Very very few tap water sources are sutiable for SW. And the ill affects take months or yrs to show. And then you wont even think its the source by then and by then curing will be much harder. Hate to see all that coral go south.
You have a hard head and have no right thinking a 4 month tank is a reason for your assumtion. If you dont rethink your reasons for what you do then just keep this thread in mind and be ready for many , I told you so's,. Anyway for waht its worth.
http://www.wetwebmedia.com/water4maruse.htm
http://saltaquarium.about.com/od/sta...opmistakes.htm