1. You are viewing the forum as a Guest, please login (you can use your Facebook, Twitter or Google account to login) or register using this link: Log in or Sign Up
    Dismiss Notice
  2. This site uses some unobtrusive cookies to store information on your computer. For more information click the following link: Cookie Usage

    Dismiss Notice

Do I need to cycle a planted tank

Discussion in 'Water Chemistry' started by paulsballs, 9 Jan 2017.

  1. paulsballs

    paulsballs Newly Registered

    Messages:
    2
    Hi I am totally new to aquascaping I have ordered a dennerle 60l cube full set up Wich comes with substrate and gravel lights and filter. I would like to do a low tech set up with a few shrimp just confused about cycling think maybe I have read to much info on the subject .
     
  2. dw1305

    dw1305 Expert

    Messages:
    5,690
    Hi all,
    You don't need to "cycle" the tank by adding ammonia, it doesn't serve any useful purpose and may inhibit the development of an appropriate microbial community.

    I like to plant the tank and then leave it to "grow in". Have a look at <"Oxygen levels required..."> and linked threads.

    If you have actively growing plants you have "plant/microbe filtration", which is much efficient and flexible than "microbe only" biofiltration.

    cheers Darrel
     
    Last edited: 9 Jan 2017
    three-fingers likes this.
  3. CaptainC

    CaptainC Newly Registered

    Messages:
    18
    Hi. Yes, the nitrogen cycle must be completed to ensure any waste products from fish or shrimp are converted into less harmful products by your filter.
    Plants can remove a little ammonia but nowhere near enough to keep water safe for your livestock.
    Please read about cycling and the nitrogen cycle.
    Enjoy your tank, scaping and feel free to ask questions.
     
  4. dw1305

    dw1305 Expert

    Messages:
    5,690
    Hi all,
    This honestly isn't true, you get it a lot in cycling posts, but you only have to look at the scientific literature for ample evidence that "plant/microbe filtration" is much more efficient than "microbe only" bio-filtration.

    A lot of people still see plants as a form of decoration, but they aren't, they are the single most important factor in biological filtration.

    There are a couple of proviso's, you need the plants to be in active growth, and bio-filtration is much more efficient if plants have <"Diana Walstad's"> "aerial advantage" of access to atmospheric gas levels.

    These are references from aquaculture, <"Nutrient removal from aquaculture wastewater using a constructed wetlands system">. <"Efficiency of aquatic macrophytes to treat Nile tilapia pond effluents">, but I have a lot more using constructed wetlands.

    There is a more complete discussion of this in <"Best way to cycle a second filter.."> (and linked threads).

    There are a number of reasons why plant microbe systems can deal with larger bioloads, but the main ones are that :
    cheers Darrel
     
    CaptainC likes this.
  5. CaptainC

    CaptainC Newly Registered

    Messages:
    18
    Hey Darrel.
    It would be interesting to see if anyone had actually managed in the real world,, outside of scientific literature/studies, has successfully managed to cycle their tank using only plants to keep non toxic levels of ammonia/nitrite. No argument that plants help uptake ammonia etc and, create conditions in substrate that promote growth of beneficial bacteria. Surely though that process will take time, I.e. A cycle, before it can support enough bacteria to keep toxic levels low enough for livestock?
    Anyone out there done this, care to comment?
    I honestly don't think I'd be willing to allow plants alone to keep levels to non toxic levels.
    I'm certainly no scientist and have not tried this method.
    Many thanks for the information, I'll read up on the subject and see what it's all about.
     
  6. dw1305

    dw1305 Expert

    Messages:
    5,690
    Hi all,
    No, <"it isn't a theoretical idea">, we do it <"all the time">.

    I've never "cycled" a filter with ammonia, there really isn't any point. We are interested in ammonia (and to a lesser degree nitrite (NO2-)) levels, because ammonia is toxic to animals, but in terms of the maturation of the tank it is much less relevant than the levels of dissolved oxygen.
    The longer you can leave the tank planted before adding the fish the better.

    I like to leave the tanks for ~6 weeks, planted and running normally, but without any livestock, but you could potentially use a floating plant, like Pistia, and assuming you had a large enough biomass of plants, add the fish straight away.
    The problem is with the cycling concept, there isn't a switch from "not cycled and toxic" to "cycled and safe" it is a continuum based on ability to deal with bioload. In the lab. you can quantify this as the <"Biochemical Oxygen Demand"> (BOD), and as a general rule if the oxygen supply exceeds the oxygen demand your tank is fish safe.

    If I was forced to keep fish in non-planted tanks I would use a wet and dry trickle filter, because of its large gas exchange surface.
    I think a lot of people feel the same. Cycling has a huge mythology built up around it and it is very difficult to get to the truth.
    In some ways that is the point, it isn't "plants alone", it is always "plants and microbes". "Plant/microbe" filtration is potentially about an order of magnitude more efficient than "microbe only filtration".

    cheers Darrel
     
    three-fingers likes this.

Share This Page

Facebook Page
Twitter Page