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Potassium Hydroxide

Discussion in 'Fertiliser - mineral supplements. Aquaponics syste' started by Murray, Mar 16, 2011.

  1. Murray

    Murray Site Admin Staff Member

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    I have obtained some supplies of high grade Potassium Hydroxide.

    I have been trailing it as a buffering agent in my systems and also to provide one of the three elements needed for AP systems that does not normally come in via the fish food.

    Just last week I found, using my "super dooper" digital pH meter that one little system (around 1200 ltrs in total) had drifted down to pH 5.43

    I added 10g (one level tablespoon) of the flaked material.

    In just 3 hours the pH had come up to pH 6.52

    A very powerful base indeed.

    I applied it in its flaked form by depositing it down the up stand coming from the fish tank, so that it would dissolve in there and be carried first to the sump and on to the grow beds that way it will be well mixed and diluted before getting back to the fish tank.

    The pH in that system is drifting down again and is now at pH 6.4

    Potassium Hydroxide of this purity needs to be handled very carefully because it dissolves readily in water generating heat as it does so. Even small amounts of moisture on the hands will start the material dissolving imparting a very greasy feel to the hands. Burns would soon follow if left on the skin. Wash off immediately.

    We are looking for suitable packaging so we can pack it down to 500g lots

    I will post more info when we have sorted out post details and it is available.
     
  2. RupertofOZ

    RupertofOZ New Member

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    Yes, be careful... this stuff is like caustic soda (pH 10.5)... but stronger (pH 12)...
     
  3. DaveOponic

    DaveOponic New Member

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    My tomatoes look like this . . . potassium deficiency?
     

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  4. RupertofOZ

    RupertofOZ New Member

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    If they're just the lower leaves Dave... then that's normal... remove them... in fact remove all leaves below the truss once fruit has set...
     
  5. Murray

    Murray Site Admin Staff Member

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    Depends a lot on the variety of the tomato bush but it does look consistent with indeterminate tomatoes.
    The lower leaves die off and do look unsightly that is for sure.

    Potassium assists in setting the fruit amongst other things and is one of the elements that is often lacking in AP systems according to the scientific types such as Dr Jim Rakocy
     
  6. DaveOponic

    DaveOponic New Member

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    I think you may be right. the tomatoes have had a lot of fruit this year. (Egg and roma varieties) The first round I planted are now coming to the end of their life cycle. We have had a handful of sweet red tomatoes every day for the past few weeks. Second round of plants in AP2 has literally kilograms of fruit that will be turning red next week and dropping on the ground while we are away in Brisbane for a week.
     
  7. tonyponics

    tonyponics New Member

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    Is there an alternative organic compound to potassium hydroxide?
     
  8. Murray

    Murray Site Admin Staff Member

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    From an earlier thread.
    More from an earlier thread
     
  9. Gigilovesfish

    Gigilovesfish New Member

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    Hi Murray. Could you please tell me if potassium could be the issue for my cotton wool fish? I have tried to get potassium hydroxide but no one seems to sell it!
     
  10. Murray

    Murray Site Admin Staff Member

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    Hi Gigi,
    Welcome.
    Please explain re "cotton wool fish"
    Potassium Hydroxide can be found in craft shops....usually. Used in soap making.
     
  11. Berto

    Berto New Member

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    Hello Murray,

    I also am in possession of Potassium Hydroxide in tablet form.
    For my 1200L system I've also added a tablespoon of the material.
    First I took some water from the system, dissolved the Potassium Hydr. tablets
    and then added the water back directly into the growbeds (after the flush) and some in the fishtank.
    This was done in the spring and we now see more fruits compared to last year.

    But when do I have to add a spoon again?
     
  12. Murray

    Murray Site Admin Staff Member

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    Just watch your plants particularly Tomatoes. It does not hurt to add some every once in a while. Usually I add some about every fourth time I buffer the pH upwards. Works for me.
     
  13. Berto

    Berto New Member

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  14. Gigilovesfish

    Gigilovesfish New Member

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    Hi Murray. Thanks for your welcome wishes :)
    The fish I have are tropical, and no matter what I do, they end up dead, wrapped in what looks like cotton wool! I cleaned tank, filter, everything very well, same problem with next batch of fish, so I chucked everything and started again, same issue. I tried changing food, less plants,less fish, but now I'm just thinking they need less of me! I don't want to give up being a fish owner, but I don't want to be a mass murderer! Help?
     
  15. Murray

    Murray Site Admin Staff Member

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    Cotton wool is a fungi. Water temp could be an issue. An old fashioned cure would be condy's crystals (potassium permanganate) Half a teaspoon per 1000 ltrs, lots of air into the tank when applied. It is anti bacterial so it does not do the beneficial bacteria much good but if treating fish in a hospital tank it is fine. Also the good old standby of salt.
     

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