New Biocube filled with Caribsea Sea Pure question?

[redbeanss]

I just bought a new biocube 14 g. I put in my Caribsea sand and new live rock and filled it with the Caribsea Sea Pure water. Do I still need to cycle my tank after using real sea water?

I tested for Nitrates and it came up zero hours after getting the tank up and running.

 

[jennm]

Yes, you still need to let the tank cycle. In 1-3 weeks or so you'll likely see a bloom of diatom algae. I would wait for that to happen at the very least, but make sure the parameters check out before adding livestock. Most people start with clean up creatures.

Jenn

 

[jennm]

Oh, and what are the specific gravity, and pH? You'll need to know what those are as well.

During the cycling period, watch for ammonia and nitrite as well as nitrate.

Jenn

 

[redbeanss]

Thanks. I wasn't sure because the label on the back of the water bottles leads you to believe that you can add fish the same day. I was planning on cycling it with the raw shrimp technique.

 

[redbeanss]

On second thought I think I'll skip the shrimp and let the liverock die off take care of it.

 

[cr500_af]

Good plan. The reason you haven't seen any nitrate readings is that nitrate is the last "toxin" phase of the cycle. You probably have ammonia detectable now, with nitrite to follow and then nitrate.

Even with seawater straight out of the ocean, the cycle is still necessary because your tank is not populated with beneficial bacteria. Very little is found in the water column; the majority is on/in the rock and sand. The ammonia from the food or dieoff will allow the growth of nitrosomas bacteria (which "feed" off of ammonia, stripping away hydrogen atoms and replacing with two oxygen atoms). This converts the ammonia into nitrite. Another form of bacteria (nitrobacter) adds a third oxygen atom, which converts the NO2 (nitrite) into NO3 (nitrate).

You need a good population of these bacteria in order to have a strong biological filter. It will build slowly, and it needs fuel to grow (which is all kickstarted by the ammonia or ammonium that your decaying matter provides as it breaks down).