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Nitrate reduction

Discussion in 'Water Chemistry' started by fishwater1, Apr 24, 2011.

  1. fishwater1

    fishwater1 New Member

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    We have a 1000L FT with two grow beds that are @ 200L, one grow bed is 3 1/2 months old and one is 3 weeks old. All of my chemistry levels were awesome prior to new bed....ammonia 0, nitrite close to 0, and nitrate 10-15 ppm. We added the new grow bed and things stayed the same until the past few days. Nitrate is not reading at all. I must also say I have posted in the past about my ph problems. I consistently have 7.4. I have been treating my water that I add to the tank with muratic acid and bringing the tap water down to 6.5 before adding to tank. It is 7.0 out of the tap but after sitting for 24 hours it goes up to about 7.6. A past thread taught me that I must have a buffer in my tap water bringing it back up to a high ph and that I should treat before I add back to tank so I have. However, not successful. I must mentiion that the plants don't look bad, except for the strawberries. My tomatoes look great...are they able to absorb all of the nitrogen? So many questions...so confused at times....thanks all. We'll start here. Should I be cautious about planting high nitrogen users into a new system or is my high ph killing my bacteria colony?:frustrated:
     
  2. Murray

    Murray Site Admin Staff Member

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    It would appear that the plants in your new bed are using up all the nitrates being produced. If your plants are looking good then don't worry. You did not have much nitrate before adding the last new bed anyway so it is not surprising that the additional bed and plantings are using it up.

    Your system is still quite young in the scheme of things and would appear to be doing well.

    You don't mention the fish in this last post. How many and how big?
    Can you increase the feed a little perhaps?

    Re pH.....7.4 is not all that bad, it would be better to be a little lower, but if it does not go any higher just wait a bit....your system is still young and all things being equal it should slowly drift down over time. The bacteria is very hardy and will be just fine at that pH. It needs material (ammonia) to flourish.
     
  3. RupertofOZ

    RupertofOZ New Member

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    Yep, everything is just fine....

    Tomatos are heavy nitrogen feeders... and it's not unusual to have a zero nitrate reading in an AP system at all.... it just means the plants are using what's available...
     
  4. fishwater1

    fishwater1 New Member

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    I am at the end of harvesting lettuce and already have grape tomato fruit....the negative reading scared me pretty much that things were off. Thanks a lot guys. You two keep my head above water....:) Fish are Koi.......started at 3" and now about 5". we have major temp fluctuations this time of year ( 42 degree cel to 85 degree cel last week) so going with a hardy fish and focus is on produce. Koi are beautiful and heavy feeders. Only 15 in right now...should I up that number? Don't know if you all are having a holiday weekend but we are so Happy Holiday weekend and cheers:
     
  5. RupertofOZ

    RupertofOZ New Member

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    Nope.... keep the fish at the level you currently have... unless you add more grow bed volume...
     
  6. snowhite7

    snowhite7 New Member

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    we have a 1,000lt tank 43 silver perch, water temp12c. System is 12weeks old. Have celery and silver beet looking good. My reason for writing is my water readings. I added urine twice, two days apart, two days later the readings are Ph 7.6-7.8,(ph has always been the same), Nitrite 2.0, Nitrate 5.0, Ammonia 0.50. Today it is Ph the same nitrite 5.0 and nitrate and ammonia the same. Is this ok? Have been given some Turtle water, when tested all was zero except the Nitrate 160ppm. Is it safe to added the turtle water to the grow beds?
     
    Last edited: Apr 26, 2011
  7. Murray

    Murray Site Admin Staff Member

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    If the turtles are healthy, but why do you think you need to? Are you worried about cycling the system?
    I am suspicious of your readings....are you sure of them? Is your test kit a new one? Are you using test strips or a Master test kit?
    I would think that the Nitrite should be diminishing and going to a zero reading.

    Just let the system settle, but check carefully the tests to make sure they are reading correctly. After 12 weeks, if there are Nitrates then the Nitrite should be diminishing and disappear.
     
  8. fishfood

    fishfood Active Member

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    Hi i would leave it alone and dont add turtle water just be patient even though your system is 12 weeks old from what you told me it dident have the requirements to cycle
    so realy your system is starting the process now
     
  9. davidl

    davidl Member

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    @snowwhite7
    Like others have said, double check your readings on the ammonia -> nitrite -> nitrate process. However adding water high in nitrate shouldn't kill your fish and will feed your plants. Like all things though there is a limit. There has been a study done as to how much is too much, and I seem to recall a number like 200 ppm shortens a fish's life, but I can't find the link I had to double check.

    I personally wouldn't feel troubled about adding the turtle water over a few days as it will be diluted by your aquaponics water's low nitrate content and the plants will enjoy it.
     
  10. RupertofOZ

    RupertofOZ New Member

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    Nitrates less than 400+ppm aren't a concern...

    Turtles are know to carry Samonella... and other parasites... I wouldn't have them any where near an AP system...

    Just feed your plants with some Seasol/Maxicrop seaweed emulsion...
     
  11. davidl

    davidl Member

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    Then it's lucky I don't have turtles or turtle water
     
  12. stimson

    stimson New Member

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    i have nitrate levels around 40-80 regularily, is this OK? What is considered too high before you need to do something?
     
  13. MattySEQ

    MattySEQ New Member

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    Answered before :)
     

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