Sudden Drop In Nitrate Level While Doing Fishless Cycle

[ggdd]

I am at the end of the third week of cycling a planted 20 gallon tank (using the shrimp method) and have been taking water sample tests every day. Yesterday my ammonia was around 0-0.25 (after peaking at 5 1 1/2 weeks ago) and nitrites were at 2. Nitrates were high at > 100. Today I measured again and found ammonia at around 0 nitrites at 1.5 and to my surprise nitrates were at 10 (no change of water)?? Thinking that I did something wrong I repeated the test with the same result. I am not sure what has happened here so any advice would be welcome. I will test again tomorrow.

 

[fatheadminnow]

Plants will use nitrates as a source of nutrients.

In my planted tank when I do weekly water changes, my nitrate level usually goes up near 5 ppm in one week. My plants use up most of the nitrates in the water.

Have you done any water changes at all?

-FHM

 

[ggdd]

No water changes yet.

I thought about the plants but the plants have been there since I started cycling the tank. Now that I think of it I did add some some seachem flourish plant supplement yesterday. I wonder if that had an effect??

 

[fatheadminnow]

No water changes yet.

I thought about the plants but the plants have been there since I started cycling the tank. Now that I think of it I did add some some seachem flourish plant supplement yesterday. I wonder if that had an effect??

It may have caused the plants to "grab" nitrate more quickly than before. (Just a theory here) Since the plants are getting more nutrients form the flourish, the plants may need to balance that out with more nitrate.

Plants are really slow to adapt to different water conditions. It can take months for plants to fully adapt to a new tank. In you situation, the plants may could be just adapting, and now since nitrate is becoming more and more avaliable to them as the cycle progresses, your plants may just be adapting and gradually taking in more and more nitrate.

All-in-all, I would not worry about it. I would be more observing of your ammonia and nitrite level at this point in your cycle, and making sure those two parameters are progressing nicely.

-FHM

 

[ggdd]

Yes I would be more worried if the ammonia levels went through the roof. I think all in all its progressing quite nicely. I also went down to our lfs and he said that the tank is getting close to being cycled and not to worry. Maybe time to start thinking about the short list for the first fish to put in??

Thanks for the reply!