Cloudy 29 gallon freshwater tank

Question
Approximately 2 weeks ago we transferred our one 11 inch regular goldfish to his new home from his old 10 gallon tank which he outgrew.  Before the transfer we rinsed for several times all the new gravel until it was clear.  Once the new aquarium was set up we added our very large fish to his new home.  After waiting at least 3 days we added more water to fill it up and then started the new filter.  The water is still cloudy after about 3 weeks.  This new filter came with the new tank (20-40 gallon tank size).

What else can I do besides every 4 days take out around 6 gallons and put in 6 new treated gallons to get it clear.
I still have our old filter.  Shall I add this filter in addition to the new one to get the tank clear?  This filter worked fine in the 10 gallon tank.  The water was crystal clear.  I would like to get this new 29 gallon tank crystal clear too.   Thanks for all your help.

Answer
Well when I started a new tank we got the filter running before we put the fish in.  You should be changeing the water every 2 weeks. I would suggest putting Aqua Safe in the tank which should help clear it up. But other then that I am clueless. Try the Aqua Safe and if it doesn't help please feel free to tell me. You can buy Aqua Safe at petsmart or probably your local fish store.
Corinna