Falling Nitrate Levels

[zootime]

I am experiencing falling Nitrate levels.
Monday levels Amm and Nitrate 0 or very low and Nitrate was at about 20.
Now all are zero or there abouts. I only have three small plants but they have always been there. Is there an explanation for this or should I even be worried. Ph 7.1
300 litre tank
Thanks for any help offered.

 

[rdd1952]

What type filter are you running and what type media do you have in it? There are types of media that say they remove nitrates. Have you done a water change in that time frame? Are you using any type of water additives or chemicals? Some will remove ammonia or nitrite which means the cycle will be broken so no nitrate will be produced. Low nitrates really aren't a problem other than your plants need some nitrate. If you are adding chemicals that are removing ammonia though, that will mean your tank will not be cycled and if youever stop using the chemicals, you will have a major problem.

 

[zootime]

I am using external filter with no carbon. or any other exotic media nor am I adding any chemicals. This set up has been running "normally" for over a year with usual weekly water changes of about 20-25%. It's just weird. Considerng I am chucking in prawns and cockles to feed my puffer fish it is even weirder!!

 

[rdd1952]

That is strange. I honestly don't know what would cause that unless teh plants are using it. As I said though, it's not a problem other than possibly for your plants.