Elevated NitrAtes

[TheChards]

Hi guys,

When I did a water test last night, I noticed that my NitrAtes had gone up slightly. Ammonia and NitrItes remained at 0ppm as they have been for the last 2 weeks (it's a newly cycled tank) but previously my NitrAtes had been at around 10-15ppm and now they've gone up to 20ppm.

Now, I know that this doesn't present a danger to the fish as I've read that levels of up to 40ppm are safe. However, I'm interested to know what might have caused this slight rise. My current thinking is that it's to do with adding new fish as more fish equals more Ammonia converted to NitrItes, NitrItes converted to NitrAtes and... I don't know where the NitrAtes go. I added 5 male Guppy at the weekend though which would seem to lend some weight to this theory.

And also, what's the best way of reducing NitrAtes? Is a large PWC the best way to get rid of them or is there something else I'm missing?

If anybody has any different ideas I'd be keen to hear them!

Thanks in advance,
Dan

 

[gzeiger]

If they're not at a dangerous level there's no need to do a larger water change than normal. Nitrate normally leaves your tank by pwc or being taken up by plants. If you have no plants, only water changes reduce them. Adding fish will raise the equilibrium level, but as long as you change some water often enough to keep it from reaching 40 you should be fine.

 

[TheChards]

Thanks for that comment gzeiger, it pretty much confirms what I thought.

I do have a few small plants in my tank although the fish have been picking on them lately and I have been taking a lot of bits of dead plant out of the water. If I've got less living plants in my tank, could that be another reason that the Nitrate level has gone up slightly? Also, am I right in thinking that plants take in Nitrate and produce Oxygen or have I just made that up?

Thanks again,
Dan

 

[jsoong]

Plants can take in nitrates, although most water plants can take in ammonia directly. If you have lots of healthy plants, you can bypass the cycle completely. Sick & dying plants, however, adds to the bioload as they decompose. At any rate, your best bet on reducing nitrates is to increase the water change. <Your nitrates had gone up 50%, so increase the pwc by the same amount ... eg from 10% to 15%>

Plants take in nitrogen (nitrates, ammonia, etc) to make proteins (ie new plant tissue). Plants takes in energy (light) for photosynthesis - converting CO2 (carbon dioxide) to sugars & starches, and releasing oxygen as a byproduct.