Posted by jane on June 16, 2005, 4:48 am
On Wed, 15 Jun 2005 21:16:14 +0100, Martin Brown
~Alex Woodward wrote:
~
~>
~>>wrote:
~>>
~>>>Is there an easy way to turn limey tap water into acidic so that I can
~>>>water
~>>>my heathers.
~>>
~>>I add a teaspoon (say 5 ml) of vinegar to a 7 litre watering-can if
~>>I'm watering ericaceous plants with tap water. It brings the pH down
~>>to about 5. Our tap water is pH 7.5, not because we are in a chalky
~>>area, quite the opposite, but many water companies add lime to raise
~>>the water pH and reduce corrosion of concrete tanks and pipework, and
~>>to assist in clarification of the water. I use vinegar because, as a
~>>weak organic acid (in the chemical sense, not the eco-friendly sense),
~>>it's broadly similar to the acids already present in peaty or acid
~>>soils, but a single drop of battery acid would probably be just as
~>>effective!
~
~Adding sulphuric acid would be marginally more effective since calcium
~sulphate is much less soluble than the acetate. Calcium fluoride is
~virtually insoluble but you could easily get yourself killed handling HF
~acid. It likes calcium far too much...
~
~>>Calcium in th water itself isn't harmful to heathers (or other
~>>ericaceous plants, for that matter), but the high pH associated with
~>>chalky soils or limey tap water means that certain trace elements,
~>>notably iron and manganese, are rendered insoluble and unavailable to
~>>the plants. Some plants (and some types of heather, especially the
~>>winter flowering types) are quite happy in these conditions, as they
~>>don't have a high requirement for iron and/or manganese, but most
~>>ericaceous plants do, so their leaves become chlorotic (yellow) and
~>>they fail to flourish. Watering occasionally with limey water probably
~>>won't do any harm, but repeated watering will eventually raise the pH
~>>of the soil, or more particularly compost if it's a potted plant.
~>
~> Thanks for an extremely informative post Chris. I'll definitely try the
~> vinegar tip. I'll use1 teaspoon full of vinegar as you suggest and give it a
~> PH test. So obvious when I think about it now, but it really did not occur
~> to me. Thanks again.
~
~He has answered your question in a strict sense. Adding vinegar will
~lower the pH, but since calcium acetate is soluble and calcium carbonate
~is not you will gradually clog up all the pores in your compost. The
~plant roots will eventually suffocate - only a matter of time.
~
~Proprietory feed mixes like miracid that stabilise the unwanted calcium
~salts in an organic complex are much better if you must use limey
~tapwater. But the simplest option by far is to use collected rainwater
~for lime sensitive plants.
I use rainwater until the butts run out then have to resort to tap, in
which case I add a capful of ericaceous fertiliser to the watering can
which I hope will offset the effect and give my camellias or
blueberries a boost at the same time.
jane
Don't part with your illusions. When they are gone,
you may still exist but you have ceased to live.
Mark Twain
Please remove onmaps from replies, thanks!
Posted by Neil Cairns on June 16, 2005, 4:18 pm
On Thu, 16 Jun 2005 08:48:43 +0000 (UTC), jane
>On Wed, 15 Jun 2005 21:16:14 +0100, Martin Brown
>~Alex Woodward wrote:
>~
>~>
>~>>wrote:
>~>>
>~>>>Is there an easy way to turn limey tap water into acidic so that I can
>~>>>water
>~>>>my heathers.
>~>>
>~>>I add a teaspoon (say 5 ml) of vinegar to a 7 litre watering-can if
>~>>I'm watering ericaceous plants with tap water. It brings the pH down
>~>>to about 5. Our tap water is pH 7.5, not because we are in a chalky
>~>>area, quite the opposite, but many water companies add lime to raise
>~>>the water pH and reduce corrosion of concrete tanks and pipework, and
>~>>to assist in clarification of the water. I use vinegar because, as a
>~>>weak organic acid (in the chemical sense, not the eco-friendly sense),
>~>>it's broadly similar to the acids already present in peaty or acid
>~>>soils, but a single drop of battery acid would probably be just as
>~>>effective!
>~
>~Adding sulphuric acid would be marginally more effective since calcium
>~sulphate is much less soluble than the acetate. Calcium fluoride is
>~virtually insoluble but you could easily get yourself killed handling HF
>~acid. It likes calcium far too much...
>~
>~>>Calcium in th water itself isn't harmful to heathers (or other
>~>>ericaceous plants, for that matter), but the high pH associated with
>~>>chalky soils or limey tap water means that certain trace elements,
>~>>notably iron and manganese, are rendered insoluble and unavailable to
>~>>the plants. Some plants (and some types of heather, especially the
>~>>winter flowering types) are quite happy in these conditions, as they
>~>>don't have a high requirement for iron and/or manganese, but most
>~>>ericaceous plants do, so their leaves become chlorotic (yellow) and
>~>>they fail to flourish. Watering occasionally with limey water probably
>~>>won't do any harm, but repeated watering will eventually raise the pH
>~>>of the soil, or more particularly compost if it's a potted plant.
>~>
>~> Thanks for an extremely informative post Chris. I'll definitely try the
>~> vinegar tip. I'll use1 teaspoon full of vinegar as you suggest and give it a
>~> PH test. So obvious when I think about it now, but it really did not occur
>~> to me. Thanks again.
>~
>~He has answered your question in a strict sense. Adding vinegar will
>~lower the pH, but since calcium acetate is soluble and calcium carbonate
>~is not you will gradually clog up all the pores in your compost. The
>~plant roots will eventually suffocate - only a matter of time.
>~
>~Proprietory feed mixes like miracid that stabilise the unwanted calcium
>~salts in an organic complex are much better if you must use limey
>~tapwater. But the simplest option by far is to use collected rainwater
>~for lime sensitive plants.
>I use rainwater until the butts run out then have to resort to tap, in
>which case I add a capful of ericaceous fertiliser to the watering can
>which I hope will offset the effect and give my camellias or
>blueberries a boost at the same time.
>Good that is what i do for my Blueberries on the allotment especialy when fruit
is forming
and i always end up with bumper yealds from 8 bushes
I am also trying Wineberry this year grown from seeds will let the
group know what they are like when they are big enough to form fruit.
>jane
>Don't part with your illusions. When they are gone,
>you may still exist but you have ceased to live.
>Mark Twain
>Please remove onmaps from replies, thanks!
Posted by Chris Hogg on June 16, 2005, 5:27 pm
On Wed, 15 Jun 2005 21:16:14 +0100, Martin Brown
>He has answered your question in a strict sense. Adding vinegar will
>lower the pH, but since calcium acetate is soluble and calcium carbonate
>is not you will gradually clog up all the pores in your compost. The
>plant roots will eventually suffocate - only a matter of time.
I find this a truly bizarre suggestion. The pore volume in a good
loamy soil is probably around 50% of the total volume. That represents
a huge amount of calcium that you'd have to deposit to block them,
compared with the amount of calcium available in the water. Even if
you argue that the micropores become clogged first, in anything other
than a bone dry soil these pores contain water (due to surface tension
and capillarity), not air. Air occupies the macropores, as do a lot of
the plant roots. So the roots won't suffocate.
And why should calcium acetate clog pores anyway? It's in solution, as
you rightly say, and apart from a small amount of base exchange with
the clay minerals and organic acids present in the soil, the bulk of
it will remain in solution, just like potassium or even the complexed
calcium you suggest is present when ericaceous fertilisers are used.
By what mechanism is this clogging supposed to occur? Where did you
get such an idea from?
--
Chris
E-mail: christopher[dot]hogg[at]virgin[dot]net
Posted by Martin Brown on June 17, 2005, 6:02 am
Chris Hogg wrote:
> On Wed, 15 Jun 2005 21:16:14 +0100, Martin Brown
>
>>He has answered your question in a strict sense. Adding vinegar will
>>lower the pH, but since calcium acetate is soluble and calcium carbonate
>>is not you will gradually clog up all the pores in your compost. The
>>plant roots will eventually suffocate - only a matter of time.
>
> I find this a truly bizarre suggestion. The pore volume in a good
> loamy soil is probably around 50% of the total volume. That represents
> a huge amount of calcium that you'd have to deposit to block them,
> compared with the amount of calcium available in the water. Even if
> you argue that the micropores become clogged first, in anything other
> than a bone dry soil these pores contain water (due to surface tension
> and capillarity), not air. Air occupies the macropores, as do a lot of
> the plant roots. So the roots won't suffocate.
All is a bit of an exaggeration I will admit, but enough of the ones
nearest the surface to hamper oxygen diffusion (and in a plastic pot
that is pretty much where oxygen has to enter to get to the roots).
> And why should calcium acetate clog pores anyway?
CO2 cuts some of it back to carbonate especially on the surface when the
dissolved salts get concentrated by evaporation. In really hard water
regions with dark compost you can see it happen over a couple of years
as the surface sets to a concrete like crust.
> you rightly say, and apart from a small amount of base exchange with
> the clay minerals and organic acids present in the soil, the bulk of
> it will remain in solution, just like potassium or even the complexed
> calcium you suggest is present when ericaceous fertilisers are used.
>
> By what mechanism is this clogging supposed to occur? Where did you
> get such an idea from?
Problems with certain epiphytic plants with high oxygen demand at the
roots. Belgian tapwater is incredibly hard even by Yorkshire standards.
Miracid and their ilk are much more effective at stabilising the calcium
in solution, but I still would not rely on it regularly for lime hating
pot plants.
Regards,
Martin Brown
Posted by Chris Hogg on June 17, 2005, 3:00 pm
On Fri, 17 Jun 2005 11:02:49 +0100, Martin Brown
>All is a bit of an exaggeration I will admit, but enough of the ones
>nearest the surface to hamper oxygen diffusion (and in a plastic pot
>that is pretty much where oxygen has to enter to get to the roots).
>CO2 cuts some of it back to carbonate especially on the surface when the
>dissolved salts get concentrated by evaporation. In really hard water
>regions with dark compost you can see it happen over a couple of years
>as the surface sets to a concrete like crust.
>Problems with certain epiphytic plants with high oxygen demand at the
>roots. Belgian tapwater is incredibly hard even by Yorkshire standards.
>Miracid and their ilk are much more effective at stabilising the calcium
>in solution, but I still would not rely on it regularly for lime hating
>pot plants.
>Regards,
>Martin Brown
OK, I can see how a surface crust might build up over a long time and
under rather extreme circumstances, but not a problem I would expect
normally and with proper attention to surface cultivation.
--
Chris
E-mail: christopher[dot]hogg[at]virgin[dot]net
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>~Alex Woodward wrote:
>~
>~>
>~>>wrote:
>~>>
>~>>>Is there an easy way to turn limey tap water into acidic so that I can
>~>>>water
>~>>>my heathers.
>~>>
>~>>I add a teaspoon (say 5 ml) of vinegar to a 7 litre watering-can if
>~>>I'm watering ericaceous plants with tap water. It brings the pH down
>~>>to about 5. Our tap water is pH 7.5, not because we are in a chalky
>~>>area, quite the opposite, but many water companies add lime to raise
>~>>the water pH and reduce corrosion of concrete tanks and pipework, and
>~>>to assist in clarification of the water. I use vinegar because, as a
>~>>weak organic acid (in the chemical sense, not the eco-friendly sense),
>~>>it's broadly similar to the acids already present in peaty or acid
>~>>soils, but a single drop of battery acid would probably be just as
>~>>effective!
>~
>~Adding sulphuric acid would be marginally more effective since calcium
>~sulphate is much less soluble than the acetate. Calcium fluoride is
>~virtually insoluble but you could easily get yourself killed handling HF
>~acid. It likes calcium far too much...
>~
>~>>Calcium in th water itself isn't harmful to heathers (or other
>~>>ericaceous plants, for that matter), but the high pH associated with
>~>>chalky soils or limey tap water means that certain trace elements,
>~>>notably iron and manganese, are rendered insoluble and unavailable to
>~>>the plants. Some plants (and some types of heather, especially the
>~>>winter flowering types) are quite happy in these conditions, as they
>~>>don't have a high requirement for iron and/or manganese, but most
>~>>ericaceous plants do, so their leaves become chlorotic (yellow) and
>~>>they fail to flourish. Watering occasionally with limey water probably
>~>>won't do any harm, but repeated watering will eventually raise the pH
>~>>of the soil, or more particularly compost if it's a potted plant.
>~>
>~> Thanks for an extremely informative post Chris. I'll definitely try the
>~> vinegar tip. I'll use1 teaspoon full of vinegar as you suggest and give it a
>~> PH test. So obvious when I think about it now, but it really did not occur
>~> to me. Thanks again.
>~
>~He has answered your question in a strict sense. Adding vinegar will
>~lower the pH, but since calcium acetate is soluble and calcium carbonate
>~is not you will gradually clog up all the pores in your compost. The
>~plant roots will eventually suffocate - only a matter of time.
>~
>~Proprietory feed mixes like miracid that stabilise the unwanted calcium
>~salts in an organic complex are much better if you must use limey
>~tapwater. But the simplest option by far is to use collected rainwater
>~for lime sensitive plants.
>I use rainwater until the butts run out then have to resort to tap, in
>which case I add a capful of ericaceous fertiliser to the watering can
>which I hope will offset the effect and give my camellias or
>blueberries a boost at the same time.
>Good that is what i do for my Blueberries on the allotment especialy when fruit