Originally Posted by RSully
If he's starting your tank with actual Live rock (truly cured LR) then yes, you will be able to add fish and inverts within a week, if not sooner. I started my tank this way and never went through a cycle at all. You can encounter problems going this route however such as unwanted hitchhikers, not to mention the cost of going this way.
I agree that if he adds cured live rock and sand that his tank will have cycled within a week. Maybe two. But that isn't why I suggest waiting two months to add a fish.
Rome was not built in a day, and I always say, "nothing good happens fast in an aquarium." Especially a Marine tank. My first tank was set up and in two weeks I had added my first fish. It was a Red-Headed Fairy Wrasse. That fish lasted a long time. I also added two clowns, a Polaris Goby, a Six-Line Wrasse and various inverts, such as shrimp and crabs and snails within the first two months. I started adding coral within the first three months and in six months I had a full reef tank going.
I started having problems. Mainly because I never took the time to make sure I understood how to properly test in an aquarium. I tested Nitrates and Nitrites and Ammonia and pH. Nitrates would hover around 5-20 ppm and Nitrites and Ammonia would be zero. pH would swing and I would add buffer to correct it. It would swing again. Livestock started dying. I figured the tank was too small, so I set up a 150.
I let the 150 sit for about two months before I started switching the livestock that survived (the two clowns, a Hippo Tang, a Mandarin and a few pieces of coral). I would move some Live Rock over and let it seed the tank. Before I added any fish I made sure that my pod population was through the roof. I started testing for Alkalinity and Calcium
. This was the key. It was a window into my aquarium that let me understand what was going on in my tank. It took me about two months to get the dosing steady before I added fish. After I started adding coral again I had a time that the Alk and Calcium was wacky again and my dosing schedule changed.
Any addition or subtraction from the tank results in swings in Alk and Calcium. Dissolved Organic Solids are neutralized by the buffers (alkalinity) in the water. Calcium is also depleted in a similiar manner, because it is the element that bonds the buffering ions (carbonates and bicarbonates) together.
This is why I say two months. It may take three weeks just to get the Alk and Calcium to the coreect initial levels (400-450ppm Calcium and 8-12 dKH Alkalinity). Then you add a C
rew. They produce waste and Alk and Calcium start to deplete again. This may take another two weeks to stabilize (and by stabilize, I mean a solid week of test results that are the same). Then you add a fish or two. Again stabilize Alk and Calcium.
Every time you add life, this proccess must be repeated until you get a good feel as to how Alkalinity and Calcium act in your tank.