Silly Question?

[lpsluver]

I live in the Ft. Lauderdale area...I just set up a new 220 and scaped it with 250 pounds of cycled rock and filled the tank with natural salt water from the Atlantic. I did this a week ago. My thoughts are the tank would not really cycle nor need to because everything was already there. I measured the NO3 last night and there was not even a trace. Am I good to go?

 

[Shane Hoffman]

Where did you get the water??? As in how close to shore?? How deep down did you draw the water from???? Whats the salinity????

 

[Randy Holmes-Farley]

Have you tried to measure ammonia? The process of setting up live rock can kill organisms on the rock and result in ammonia in some cases.

 

[lpsluver]

at least 20 miles off of the Ft. Lauderdale coast and I cannot speak to the depth. Many of us purchase from a guy that has this as part of his business. He is very trust-worthy. The salinity was 1.026 and was adjusted down to 1.024 for the FOWLR tank that I have set up.

 

[lpsluver]

Have you tried to measure ammonia? The process of setting up live rock can kill organisms on the rock and result in ammonia in some cases.

No. The rock was fully cycled and odorless, so I do not believe I need to. At this point if I had ammonia I believe I'd be registering some nitrate.

 

[lordofthereef]

There are differing opinions on this topic. I am of the opinion that if you put cycles media into the tank, there is no new cycle needed to be performed. I have had success doing it this way as well. I see no reason to wait for a cycle, however I find it helpful to get some peace of mind and just toss some dead matter (people like to say shrimp) in there, let it decay, and take some readings. In a tank that size, you will probably not even register much from a small piece of shrimp if you biological filters are established (as they should be on precycled rock). One thing to keep in mind though is that for these bacteria to stay alive in the appropriate numbers they do need to be fed, so they will need an ammonia source, otherwise they start to die off.

 

[seapug]

It's possible to have a very brief or practically non-existent cycle when you set up a tank as you have, but just because you don't have nitrate doesn't automatically mean the tank has cycled. It could also mean that your cycle hasn't even begun. You can consider it cycled when you get undetectable ammonia, nitrite, and no (or very low) nitrate.

If that's the case, you may have skated by with a very brief or non-existent cycle, but I'd still avoid going out and spending $1500 on fish and corals this weekend and dump them in the tank. I'm a believer in the idea that it's impossible to test for every parameter that makes a tank habitable and there are some that only come with time.

Your tank may be cycled, but its capacity to biologically process ammonia is likely still a bit weak and unstable, so I'd still take it slow for the first couple months.

 

[Randy Holmes-Farley]

At this point if I had ammonia I believe I'd be registering some nitrate.

You may not have ammonia, but I'd try to measure it before adding organisms. Lack of nitrate means nothing in this context, IMO. Raw live rock may not show nitrate after 1 week, but will often show ammonia and isn't cycled.