cycle ?

[mark humme]

I have a 20 gal tank that I've recently changed over to saltwater after much research. I have 20lbs LS, 3lb LR, 2 domino damsels, 2 yellow tail damsels and a red burrowing crab. I have a sea clone 100 protein skimmer, penguin 125 hang on filter, and a small sub. pump to bottom current.
My tank has been cycling for about 4 weeks
ph 8.2
amm 0.25
nitrite 0
nitrate 10
Is it normal for the nitrite to go to 0 before the ammonia?
The amm was at .50 maybe a little higher, and the nitrite toped out at .50. I've tested it twice in the last two days and that's how's it's held. I was expecting the ammonia to fall to 0 first.
Does this mean that my tank is almost cycled?
Will adding more live rock this weekend mess up my cycle?

 

[dskidmore]

Some test kits aren't completely accurate. Try overfeeding the tank once and tracking the nutrients. If ammonia goes up and back down, or stays steady, you're set to go.
As far as adding rock, it depends on the rock. Fully cured rock, especially fully cured obtained locally, should not have much effect on your tank. It would only be a minor ammonia spike like overfeeding the tank would do. Uncured rock, or rock that spends days in shipping may restart your cycle. I suggest putting it in a seperate container for curing first. If a seperate container cure isn't practical, add the rock a small ammount at a time, so you get several small ammonia spikes, instead of a whopper that will hurt the fish.

 

[mark humme]

thanks d,
I will be aquiring the rock locally, I overfed the tank tonight about how long should I wait to recheck the levels?

 

[dskidmore]

Not sure exactly, I'd guess within the first 24 hours you'll see the ammoia spike, then it should go back to normal. My uncertianty is why I added "or stays steady" to the previous suggestion. If your biofilter is really hyped up, it will process the extra nutrients too quickly to notice. If you have an insufficient biofilter, the ammonia and/or nitrites will go up and stay up for a day or two.

 

[mark humme]

thanks for your help just retested and everything is still where it was yesterday around the same time. I'm going to take soem water down to the LFS on saturday just to de sure my test kit is not giving me false readings.