Cycling Question

[Mike&Diana]

I am currently "cycling" two tanks.. I was forced to do a cycle w/ fish because of extraordinary circumstances in one tank. The other is being set up completely fishless. Anyhow, I am doing careful monitoring of the tank that has fish as well as frequent water changes to minimize the toxins in the tank. Yesterday I took measurements and found trace levels of ammonia and zero nitrites. I figured, awesome, the tank is cycled. I then went out and purchased a test kit with a nitrate test. I tested the water and got pretty substantial nitrate readings. Well, this morning I decided to test my tap water and sure enough, it has a lot of nitrates as well. However, the tank levels are still a little bit higher... but not by much! I just tested again and found trace ammonia, zero nitrites, and a good amount of nitrates. My question is, is the tank cycled... or has it barely begun? I was fooled by the zero nitrite reading and the high nitrate reading... but the nitrates could be from the tap water. The puzzling question is, since the nitrates are a little bit higher in the tank versus in the tap, should I have anything to be worried about? Has the cycle barely begun? Or is it almost finished? Thanks for your advice!

Mike

 

[dwarfgourami]

Almost finished, I'd say. The cycling will never get rid of the nitrates for you, that's one reason we do water changes. Nitrates are the end product of the cycle. Having plants will help to consume the nitrates though.

 

[TwoTankAmin]

A cycled tank has 0 ammonia and 0 nitrites.

A tank cycles in a specific order. The chart below illustrates the process

from FINS

Your tank is not cycled nor close to cycled as long as you have any ammonia readings at all.

 

[rdd1952]

Your tank isn't cycled since you still have ammonia. I would continue to do water changes while you have ammonia and nitrite readings. How large is the tank and what/how many fish are in it?

 

[Mike&Diana]

It is a 40G tank with about 10 small fish. I am going to keep up with the water changes - how often should I do it to protect the fish as much as possible? And what explains the nitrate readings? Will a partially cycled tank show nitrates? Like I said, there are zero nitrites. From what I understand, nitrates are a byproduct of nitrites. My tap water does contain nitrates, but the tank shows much more than the tap now. Thanks everyone!

Mike

Okay, I just tested again this morning. I tested both my tap and tank water. I got ZERO nitrIte readings for both. This time, the tap water has 0 ppm nitrAtes. The tank is reading almost 10 ppm. The ammonia levels in the tap are obviously 0 ppm. The level in the tank is about .25 ppm (very low). I am still confused. I am still showing trace ammonia levels, zero nitrItes, but have nitrAtes. Any advice will be much appreciated!

 

[Mike&Diana]

Anyone have some insight into the situation? I am sorry to bump this back up...

 

[tttnjfttt]

You are definately on the way to having a cycled tank, but not quite there yet. My guess as to why you have nitrates and ammonia but no nitrite is that when you were diligently doing water changes, the bacteria that turn the nitrite into nitrate developed faster than the ones that turn ammonia into nitrite. This is definately out of the ordinary, but if the highest spike you have gotten is .25, you are doing a great job with the water changes, and just keep it up until you see the ammonia and nitrite zero for a few days, then slowly scale it back, making sure they don't build back up.