How long dose it take to cycle a salt water fish tank

Question

i have a 20 gallon salt water fish tank it has 5 pounds of live rock and live sand its been running for 2 weeks and i have put fish food in how long dose it take till it cycles

Answer 1

The only real way to tell is to do your water tests.  Everytank is different.

Once you see the ammonia spike anything above 1 then drop it is coming down off its cycle.

Also, do not confuse a cycled tank with a matured salt water tank.  Higher end species of fish need a matured tank, that is where the bacteria have fully matured (around 6 months to a year).

Test the water.  That is how you will know.

Answer 2

Personally one of the best ways to cycle a salt water tank when you first start is by taking the salt that you would add and setting it to the side.  Buy some Black Mollies.  They are brackish fish and can transition from freshwater to salt water.  They are also cheap.  Over the course of several days, keep adding the  salt until it is the recommended saline solution for salt water.  

If you want to start with salt water fish.  Damsels are generally the cheapest and hardiest to establish the tank with.

I am not all that familiar with live rock and live sand but I do not really see how you can establish the bacterial action that you need to cycle the tank without some live fish in the tank.