Page 1 of 5 123 ... LastLast
Results 1 to 15 of 73

Thread: Dry Fertilisers - Source and Recipe

  1. #1
    Join Date
    Jun 2006
    Location
    Coffs Harbour NSW
    Posts
    1,917

    Default Dry Fertilisers - Source and Recipe

    This is a subject that comes up time and time again and various bits of information are contained in several posts scattered around this site.
    I thought it might be helpful to pull it together into a single post and place here.

    PMDD (Poor Mans Dosing Drops or Poor Mans Dupla Drops)

    PMDD was originally developed by the Canadians Conlin and Sears. Their aim was twofold, or come up with a solution to common algae problems and develop a fertiliser that was cheaper and more readily available than commercial brews from Aquarium shops.

    At the time, it was common belief that excess Phosphates were the key cause of algae in aquariums and by limiting the uptake of Phosphates, algae growth could be reduced.

    Plant nutricients are largely categorized into two categories, or Macro nutricients and Micro nutricients.

    Macro nutricients (often referred to as NPK) include Nitrate, Phosphate and Potassium while Micro Nutricients are commonly referred to as Traces or Trace Elements and include minerals such as Iron (Fe), Boron, Molybdenum, Copper, Manganese, Zink and others.
    Micro nutricients are normally sourced pre-mixed while the Macros are usually sourced in pure or almost pure form.

    The main Macros are Nitrate, Phosphate, Potassium, Calcium and Sulphur
    The main Micros are Iron, Copper, Boron, Manganese, Molybdenum, Zinc, Chloride and Nickel.

    PMDD is based on the theory that if you supply plants with sufficient and well balanced amount of nutricients but leave out the Phosphate, Phosphate becomes the "limiting factor" and therefore algae growth is kept under control.

    Because of this theory, PMDD doesn't contain any Phosphate but is rich in Potassium and Magnesium.

    Recipe
    The recipe below is quite close to the original Conlin / Sears formula and is still valid as a good start for most planted aquariums:

    15g Chelated Trace Element Mix
    25g K2SO4 (potassium sulfate)
    10g KNO3 (potassium nitrate)
    55g MgSO4.7H2O (epsom salts)
    500mL filtered or distilled water

    Warm up in a saucepan 500mL filtered water or distilled water and mix in the dry ingredients. Stir well until all is dissolved. Leave to cool and pour into a 500mL bottle. Store refrigerated.

    Source
    All of the above are available from Aquagreen and Aquagrow at quite a reasonable price.

    Chelated Trace Element Mix (Simplegrow Traces, Yates Trace Elements, - Bunnings, Nurseries)
    K2SO4 (potassium sulfate) (Aquagreen, Aquagrow, Yates Sulphate of Potash - Bunnings, Nurseries)
    KNO3 (potassium nitrate) (Aquagreen, Aquagrow, Chemists, Chemical Supplies)
    MgSO4.7H2O (epsom salts) (Aquagreen, Aquagrow, Bunnings, BigW, Nurseries)

    Dosing
    For an average, medium light tank (1.5 - 2.5W/Gal) with medium plant mass, start with a daily dose of 2mL per 100L of tank water.

    I hope this is of some help to the ones who are trying to get their head around the use of PMDD.

    If you are interested in knowing about symptoms of the various nutricient deficiencies , check out this link:
    http://www.finostrom.com.gr/images/a...lizers/map.htm

    For target volumes and dosing, you can't go wrong with Chuck Gadd's calculator:
    http://www.csd.net/~cgadd/aqua/art_p...osage_calc.htm
    Or download an offline copy:
    http://www.csd.net/~cgadd/aqua/art_plant_aquacalc.htm
    Last edited by apalsson; 19-11-07 at 03:26 AM. Reason: Updated source list

  2. #2
    Join Date
    Jul 2007
    Location
    Graeme sent me to the Naughty Corner!
    Posts
    8,158

    Thumbs Up

    that first link is great, informative thread too! thanks for all that info
    He's not the messiah, he's a very naughty boy!

  3. #3
    Join Date
    Jul 2007
    Location
    South Coast NSW
    Posts
    1,007

    Default

    Great post.

    What would be the most popular fertilizer regime now for Aussie plant aquarists PMDD or EI ?

  4. #4

    Default

    Do you mean for Aussie plants or Aussies that keep other non-native plants?

  5. #5
    Join Date
    May 2006
    Location
    Bellarine Peninsula, Victoria
    Posts
    5,910

    Thumbs Up Top Post

    Good post Ari.

    I for one am no expert on this subject and appreciated posts like this to further my knowledge.

    Well done.
    [SIGPIC][/SIGPIC]

  6. #6
    Join Date
    Jul 2007
    Location
    South Coast NSW
    Posts
    1,007

    Default

    Quote Originally Posted by SOLOMON View Post
    Do you mean for Aussie plants or Aussies that keep other non-native plants?
    Australian aquarists keeping planted aquaria

  7. #7

    Default

    I dont think what i wrote reflected what i meant, basically that there is no set guideline to the way you should dose. PMDD is a good alround fertiliser regime while EI you can specialise in certain areas. Australian plant however prefer less fertilisation than others, due to our poor soil fertility, so it may be better in this case to use EI.

  8. #8
    Join Date
    Apr 2007
    Location
    Sydney
    Posts
    732

    Default

    Thanks Ari

    A very good summary

    I too am far from an expert. I think it is particularly useful that you have given a starting point for a medium light tank with a medium plant load. That should make it easier for me to tailor a fert regime to my own tank once I learn the signs of nutrient deficiencies.
    Last edited by Matt31; 31-08-07 at 10:38 PM.
    Regards

    Matt

  9. #9
    Join Date
    Jun 2006
    Location
    Coffs Harbour NSW
    Posts
    1,917

    Default

    Quote Originally Posted by Jim View Post
    What would be the most popular fertilizer regime now for Aussie plant aquarists PMDD or EI ?
    Hi Jim,

    Tom Barr's Estimative Index (EI) actually builds on the use of similar methods as what I have described with the difference being that in his methods, you add enough nutricients into the tank to ensure that no single one becomes in short supply.
    You then "reset" the tank each week by doing a large waterchange.

    EI is particularly popular in the USA but as a lot of Native Australian plants come from nutricient poor areas, they don't seem to take too well to high nutricient levels.

    Tom's methods are also mostly aimed at the so called "high tech" tanks where you have intense lighting and efficient CO2 injection.

    You may find that in the "average tank" with "medium lighting", the Conlin Sears method still works quite well.

    Please note though that the Conlin Sears method is quite old now and people have since challenged some of the theories, especially in regards to dosing Phosphates but the core of it still reamins in widespread use.

    I personally use the Conlin Sears method but have increased the dosing somewhat and also dose Phosphates in my tanks.

  10. #10
    Join Date
    Jul 2007
    Location
    South Coast NSW
    Posts
    1,007

    Default

    Apalsson, your post is the sort of info that is eagerly sort by people new to ferts. You should sticky it so that it doesn't get buried away.

    Your tank also looks awesome, so you should put a pic up in this thread of your tank as well.

  11. #11
    Join Date
    Jul 2007
    Location
    Lismore, NSW
    Posts
    572

    Default

    If I were to go into a chemist or chemical supplier and ask for Potassium Nitrate, they would assume I'm a terrorist or ask me for an ABN or something. What product would you ask for that contains KNO3 so people including me don't make an idiot of themselves?

  12. #12
    Join Date
    May 2007
    Location
    Melbourne, Roxburgh Park
    Posts
    2,266

    Default

    Great post apalsson!
    Much valuable info and a great explanation.

    I now know now my tank is a medim light tank

  13. #13
    Join Date
    Jun 2006
    Location
    Coffs Harbour NSW
    Posts
    1,917

    Default

    Quote Originally Posted by pelvis_3 View Post
    If I were to go into a chemist or chemical supplier and ask for Potassium Nitrate, they would assume I'm a terrorist or ask me for an ABN or something. What product would you ask for that contains KNO3 so people including me don't make an idiot of themselves?
    Pelvis, no this is not necessarily the case.
    If you ask for 10 kgs, yes, they will check on you but if you ask for 500g, they will sell it to you. You would ask for Potassium Nitrate.
    Another name for it is Salt Peter.

    The chemist would be quite expensive though because they will be using lab grade chemicals whereas you can buy a Kg from Aquagreen or Simplegrow for much less.

  14. #14
    Join Date
    May 2006
    Location
    Bellarine Peninsula, Victoria
    Posts
    5,910

    Default

    I just oredered some from Dave at Aquagreen. For 500grams cost was less then 2 dollars.

    OK you have to add shipping, but I ordered plants and shrimp so the postage is not that high in the end.
    [SIGPIC][/SIGPIC]

  15. #15
    Join Date
    Jun 2006
    Location
    Coffs Harbour NSW
    Posts
    1,917

    Default

    Quote Originally Posted by Jim View Post
    Apalsson, your post is the sort of info that is eagerly sort by people new to ferts. You should sticky it so that it doesn't get buried away.

    Your tank also looks awesome, so you should put a pic up in this thread of your tank as well.
    Thanks for the kind commets Jim,

    My tank doesn't look all that flash at the moment, months of neglect and lack of maintenance plus my Tunze CO2 reactor is a non-stop source of problems.
    I think I might throw it in the bin and set up a DIY unit.
    But at least, the plants are growing like weed (well, most of them)

Page 1 of 5 123 ... LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •