Nitrate reading is 0... What does this mean? Question

  1. cwb141 Member Member

    I have a 29 gallon, semi-planted, freshwater tank. Already cycled and been up since May. I was using ML Special Blend until a couple weeks ago and didn't notice anything strange with test results until today, nitrate was 0 (3 times, API Master Freshwater). I haven't added anything since then and have done 2 water changes (20%).

    I've been looking all over for what a nitrate level of 0 means and the closest thing to an answer I can find is that the closer to 0 the better. All I can think of is that the plants in the tank are absorbing it all, but I still have algae growing...

    Anyone have any ideas on why it's 0? I'm assuming this is great for the fish, but is there reason for worry?
     
  2. iloveengl Well Known Member Member

    It's quite likely that once you stopped using ML Special Blend, which creates a false cycle if not added every week or two, your tank is beginning the true cycling process.

    Keep a very close eye on your ammonia and nitrite.

    A cycled fw tank will have nitrates unless it is heavily planted, and it doesn't sound like yours is planted enough to cause that.
     

  3. Lucy Moderator Moderator Member

    A couple of ideas come to mind.
    1) You have enough plants to absorb the nitrates.
    2) Your tank isn't truly cycled. The Special Blend might be removing the ammonia and nitrites but the bacteria that converts nitrites to nitrates isn't present.
    3) The #2 nitrate bottle contains crystals (the other tests are purely liquid). If you don't shake, bang and otherwise abuse the #2 Nitrate bottle to thoroughly mix the crystals you could get a false 0 reading.
     
  4. cwb141 Member Member

    I had nitrates a few days ago. If the plants absorb the nitrates does this also mean the plants will not be getting enough?

    I doubt my tank is planted enough for that. I'll check it again next week, maybe the tank needs to find a new equilibrium now that I'm not adding anything to it. I'm guessing there are mini-cycles anytime you add something to the tank, or don't continue adding something.

    I didn't do a superb job on the testing so I did it all over again exactly right and the only thing that changed was my pH being slightly more acidic at 6.4

    *less acidic at 6.4

    :animal0068:Good morning. I've merged your posts since there was no response between. Don't forget about the "Edit" key at the bottom of every post that you can use for corrections or additional thoughts when there are no responses.
    Thanks!
    Ken

    Hi Ken, good morning to you too, lol.
     

  5. Shawnie Fishlore Legend Member

    I agree with the others..keep an eye on your ammonia/nitrites and if you can go another week or so of not adding anything, and still have a 0 for them, I think you are in the clear!! and then you can write it up to your plants eating them....
     
  6. cwb141 Member Member

    Went through a mini cycle after some problems. All good now. Readings are pH 6.8, Ammonia 0, Nitrite 0, and Nitrate 5. Only difference from before this issue is pH closer to neutral. I think the amount of tannic acid leaching from a piece of driftwood has slowed down, evidenced by longer time to turn water to tea color and rise in pH from 6.4 to 6.8. I'm guessing the plants clear up the most of the nitrates. A couple years ago (same tank, filter, fish load) my nitrate readings were higher with fake plants as compared to now.