I got a bag to try on my lawn. The instructions said to use a number
(which I can't recall right now - 25 maybe) of grams per square metre.
Trouble is, I've no idea what that looks like. If anyone here uses it,
can you tell me how many teaspoons you use :-)

On 4/15/2016 9:45 AM, Dan S. MacAbre wrote:
I got a bag to try on my lawn. The instructions said to use a number
(which I can't recall right now - 25 maybe) of grams per square metre.
Trouble is, I've no idea what that looks like. If anyone here uses it,
can you tell me how many teaspoons you use :-)

Put a nice clean container on your kitchen scales, tare, and weigh it out.

On 15/04/16 14:45, Dan S. MacAbre wrote:
I got a bag to try on my lawn. The instructions said to use a number
(which I can't recall right now - 25 maybe) of grams per square metre.
Trouble is, I've no idea what that looks like. If anyone here uses it,
can you tell me how many teaspoons you use :-)

About 3 slightly heaped. Basically, it doesn't matter as it's not
critical. But better to do slightly less than more, as too much could
"burn" the lawn. Some interesting comments here (particularly the third
one by Hoots):
http://www.lawnsite.com/threads/anyo...ulfate.243198/

--

Jeff

On 4/15/2016 10:43 AM, Chris Hogg wrote:
On Fri, 15 Apr 2016 14:45:44 +0100, "Dan S. MacAbre"
wrote:
A level standard teaspoon holds 5ml, which
will be about 5g of ammonium sulphate, so three level teaspoons per
sq.metre will be roughly right.

Are you quite certain on that measurement? 5ml of _water_ weighs 5g -
but I'd be surprised if 5 ml of ammonium sulphate does.

On 15/04/2016 16:20, Chris Hogg wrote:
On Fri, 15 Apr 2016 11:10:54 -0400, S Viemeister
wrote:

On 4/15/2016 10:43 AM, Chris Hogg wrote:
On Fri, 15 Apr 2016 14:45:44 +0100, "Dan S. MacAbre"
wrote:
A level standard teaspoon holds 5ml, which
will be about 5g of ammonium sulphate, so three level teaspoons per
sq.metre will be roughly right.

Are you quite certain on that measurement? 5ml of _water_ weighs 5g -
but I'd be surprised if 5 ml of ammonium sulphate does.

I'm assuming that the ammonium sulphate is loose packed, so would have
a lower density than the pure solid. As a rough check, 5ml of loose
potassium chloride weighs 5.5g. Within the accuracy needed for such
things (it's not analytical chemistry, after all) assuming a
loose-pack density of 1g/ml is probably quite good enough.

I note also that Jeff recommended a similar amount, although he did
say three slightly heaped teaspoons.

I really would weigh it out to start with I have several teaspoons here
all of which are different sizes. So unless you want to use kitchen
spoon measures................

On 15/04/16 16:20, Chris Hogg wrote:
On Fri, 15 Apr 2016 11:10:54 -0400, S Viemeister
wrote:

On 4/15/2016 10:43 AM, Chris Hogg wrote:
On Fri, 15 Apr 2016 14:45:44 +0100, "Dan S. MacAbre"
wrote:
A level standard teaspoon holds 5ml, which
will be about 5g of ammonium sulphate, so three level teaspoons per
sq.metre will be roughly right.

Are you quite certain on that measurement? 5ml of _water_ weighs 5g -
but I'd be surprised if 5 ml of ammonium sulphate does.

I'm assuming that the ammonium sulphate is loose packed, so would have
a lower density than the pure solid. As a rough check, 5ml of loose
potassium chloride weighs 5.5g. Within the accuracy needed for such
things (it's not analytical chemistry, after all) assuming a
loose-pack density of 1g/ml is probably quite good enough.

I note also that Jeff recommended a similar amount, although he did
say three slightly heaped teaspoons.

Indeed - I waved an informed finger in the air!!

According to Wikipedia the density of ammonium sulfate is 1.77.g/cm^3
(the density of potassium chloride is a little higher - 1.98). But of
course that would be as a single lump; in that case, 5ml of ammonium
sulfate would weigh just under 9g. It's the bulk density we are really
interested in and that depends on a lot of things. But, as you and I
agree, it's not exactly critical.

--

Jeff

In article , david@abacus-
nurseries.co.uk says...

On 15/04/2016 16:20, Chris Hogg wrote:
On Fri, 15 Apr 2016 11:10:54 -0400, S Viemeister
wrote:

On 4/15/2016 10:43 AM, Chris Hogg wrote:
On Fri, 15 Apr 2016 14:45:44 +0100, "Dan S. MacAbre"
wrote:
A level standard teaspoon holds 5ml, which
will be about 5g of ammonium sulphate, so three level teaspoons per
sq.metre will be roughly right.

Are you quite certain on that measurement? 5ml of _water_ weighs 5g -
but I'd be surprised if 5 ml of ammonium sulphate does.

I'm assuming that the ammonium sulphate is loose packed, so would have
a lower density than the pure solid. As a rough check, 5ml of loose
potassium chloride weighs 5.5g. Within the accuracy needed for such
things (it's not analytical chemistry, after all) assuming a
loose-pack density of 1g/ml is probably quite good enough.

I note also that Jeff recommended a similar amount, although he did
say three slightly heaped teaspoons.

I really would weigh it out to start with I have several teaspoons here
all of which are different sizes. So unless you want to use kitchen
spoon measures................

I weigh one measured dose on the scales in a little plastic cup (from
liquid laundry detergent) and mark the cup with a felt-tip to show
where the measured dose came to.

Subsequent measures don't need to be weighed; just fill the cup to the
mark.

Janet.

On 15/04/2016 16:26, David Hill wrote:
On 15/04/2016 16:20, Chris Hogg wrote:
On Fri, 15 Apr 2016 11:10:54 -0400, S Viemeister
wrote:

On 4/15/2016 10:43 AM, Chris Hogg wrote:
On Fri, 15 Apr 2016 14:45:44 +0100, "Dan S. MacAbre"
wrote:
A level standard teaspoon holds 5ml, which
will be about 5g of ammonium sulphate, so three level teaspoons per
sq.metre will be roughly right.

Are you quite certain on that measurement? 5ml of _water_ weighs 5g -
but I'd be surprised if 5 ml of ammonium sulphate does.

I'm assuming that the ammonium sulphate is loose packed, so would have
a lower density than the pure solid. As a rough check, 5ml of loose
potassium chloride weighs 5.5g. Within the accuracy needed for such
things (it's not analytical chemistry, after all) assuming a
loose-pack density of 1g/ml is probably quite good enough.

I note also that Jeff recommended a similar amount, although he did
say three slightly heaped teaspoons.

I really would weigh it out to start with I have several teaspoons here
all of which are different sizes. So unless you want to use kitchen
spoon measures................


A standard teaspoon (as used to be provided with cough mixtures, et al)
is 5ml, so I always keep one of those handy. However, 5ml of liquid is
necessarily level. Dry teaspoon measures can be either 'level' (level
with the top edge of the spoon), 'rounded' (the dry content should
mirror the bowl of the spoon) or 'heaped' (the dry content should be as
near twice the mirrored bowl of the spoon as is practical.

--
Spider
On high ground in SE London
Gardening on heavy clay

On Fri, 15 Apr 2016 18:30:47 +0100, Janet wrote:


I weigh one measured dose on the scales in a little plastic cup (from
liquid laundry detergent) and mark the cup with a felt-tip to show
where the measured dose came to.
Subsequent measures don't need to be weighed; just fill the cup to the
mark.


Just what I did yesterday for lawnfeed, also marked a dozen canes a
meter long to get the area right.
www.lincolnfuchsiasociety.info

Dan S. MacAbre wrote:
I got a bag to try on my lawn. The instructions said to use a number
(which I can't recall right now - 25 maybe) of grams per square metre.
Trouble is, I've no idea what that looks like. If anyone here uses it,
can you tell me how many teaspoons you use :-)

Thanks everyone for the advice. We don't have kitchen scales, since
both the missus and I believe that 'the spoonful' is an accurate enough
measure. I do have digital luggage scales (wouldn't dare go on holiday
without one, these days), which just might be accurate enough, but I'm
not going to bet a huge amount of money on it.

Dan S. MacAbre wrote:

Thanks everyone for the advice. We don't have kitchen scales, since
both the missus and I believe that 'the spoonful' is an accurate enough
measure. I do have digital luggage scales (wouldn't dare go on holiday
without one, these days), which just might be accurate enough, but I'm
not going to bet a huge amount of money on it.

Presumably it came in an e.g. 5kg bag? Squish that into a rectangular
shape, measure the sides, and you can calculate the volume. Then just do a
bit of long division to work out the volume per dose, and find your little
measuring thing from the soap. That should be calibrated in volumes, and
if not it is relatively trivial to calculate from pi*r^2*h

Robert Harvey wrote:
Dan S. MacAbre wrote:

Thanks everyone for the advice. We don't have kitchen scales, since
both the missus and I believe that 'the spoonful' is an accurate enough
measure. I do have digital luggage scales (wouldn't dare go on holiday
without one, these days), which just might be accurate enough, but I'm
not going to bet a huge amount of money on it.

Presumably it came in an e.g. 5kg bag? Squish that into a rectangular
shape, measure the sides, and you can calculate the volume. Then just do a
bit of long division to work out the volume per dose, and find your little
measuring thing from the soap. That should be calibrated in volumes, and
if not it is relatively trivial to calculate from pi*r^2*h


Calculate the density - good idea!