Oxalic acid from P****s

[Finman]

When we started selling the ready-mixed solution, we approached our Regional Bee Inspector about it and after he took some away for tests, he advised that it is perfectly safe to use straight from the bottle.

We've used it ourselves for the past 4 or 5 years and find we get good results from it."

NICE! Where we need debate when "regional inspector knows everything".

http://www.culturaapicola.com.ar/apuntes/revistaselectronicas/apidologie/37-1/13.pdf

Trials in which more than 3.5% oxalic acid
dihydrate solution were applied showed that
higher dosages do not clearly lead to an
increased efficacy (Charrière, 2001; Charrière
and Imdorf, 2002; Liebig, 1998; Nanetti et al.,
2003a). There is a tendency that the highest
concentrations and doses of 6 or 8% (Liebig,
1997, 1998) actually reduced the efficacy.
Using these high dosages to combat varroosis
is not feasible because the bees cannot tolerate
them (see Sect. 1.1.2 Tolerability).

 

[Finman]

When we started selling the ready-mixed solution, we approached our Regional Bee Inspector about it and after he took some away for tests, he advised that it is perfectly safe to use straight from the bottle.

We've used it ourselves for the past 4 or 5 years and find we get good results from it."

6% solution is based an early studies about trikcling. 4% is those early studies too.

http://www.db-alp.admin.ch/en/publikationen/pub_detail.php?id=17426 Last modification: 09.10.2008

Solutions.....Oxalic acid solutions with 30 g, 37 g and 45
g OA dihydrate per litre sugar water

++++++++

The effectiveness of the three solutions was
not significantly different, while the effect of
the 30-g solution was slightly less than that
of the other two. This suggests that this
concentration lies at the lower limit and that
therefore the dosage cannot be further
reduced without interfering with effectiveness.
These observations confirm the
results of 1998 with this same solution8
(decrease and greater scatter of the effectiveness
compared with higher dosages), as
well as those of Büchler6.

 

[Finman]

.
Recommendations for the trickling
treatment with oxalic acid
(Switzerland and central Europe).
Composition of the solution:
35 g oxalic acid dihydrate in 1 litre sugar
water 1:1
Amount of solution:
● 30 ml for a small colony
● 40 ml for a medium-sized colony
● 50 ml for a large colony
This amount corresponds with 5–6 ml
per occupied bee space in a Dadant or
Swiss hive
Timing of the treatment:
in broodless colonies (November–
December)
Remarks:
● Carry out one treatment only in
autumn
● Trickle the solution directly onto the
bees between the frames
● Treat with lukewarm solution
● Carry out treatment at an outdoor
temperature of above 0°C
● Use only freshly made-up solutions, or
those stored for no more than 6
months at a maximum of 15°C4,32
● Under certain conditions a trickling
treatment with oxalic acid can lead to
a slight weakening of colonies in spring
● The spray treatment with oxalic acid
is well tolerated by bees (30 g OA
dihydrate/litre water, 3–4 ml per occupied
frame side)9 and represents an
alternative to the trickling method
●Wear gloves and saf

 

[arl]

Finman
pm sent

 

[Finman]

.
we have 30% sugar and oxalic acid 6%.
What we have to do to get 1:1 syrup and 3,5% OA


100g bottle stuff has

sugar ... 30 g.................add 50 g --> 80 g
water ... 64 g .................add 16 g --> 80 g
OA........6 g..........................................6 g

...............................6/166 = 3,6%

if we add water 20 g (4 g more) = 6/170 = 3,5%

So we get 70% more trickling stuff : 100 ---> 170 g

 

[arl]

Right There should be a picture here now, of the label,
And I thought this was going to be easy, go to shop buy OX_Acid as recommended, (get the made up stuff as you don't know what your doing yet) open hive and trickle 5ml per seam of Bees.
Q. is this stuff safe to use YES or NO please
Thanks
Tony

 

[dickbowyer]

Tony

That is the stuff I bought from P****s. Think I might dilute as per Finman..............

 

[Finman]

is this stuff safe to use YES or NO please
Thanks
Tony

What I read about that stuff, it is based on early knowledge over 10 years ago about trickling when varroa group started its researches.

The value of oxalic acid in the bottle is some cents.

ARL, bye a digital kitchen balance and add into stuff water and sugar.

 

[gavin]

Tony

That is the stuff I bought from P****s. Think I might dilute as per Finman..............

I don't thin that Finman's calculations are right, but it would still be better than 6% in 30% syrup.

Finman: when you dissolve sugar you don't add that volume to the total. The density of the solution rises, and the volume is less that the total.

G.

 

[arl]

Right ,
Thanks Finman,
My maths are a bit rusty but this is 1/2 ltr bottle on label.
Which is 500g, or 500ml, yes ?
so I will have to x5 all your amounts in post #25

sugar add 250g
water add 74g
then I got lost with the extra water,

or do I half the amount in the bottle, so I start with 250g and then double your amounts in post #25,
so that would be

sugar sugar add 125g
water add 37g
Sorry to be a pain, but have I got it right? nearly

 

[gavin]

Hi Arl and All

OK, here is my best attempt, now that it is clear you have a 500ml solution that is due to be made up to 1 litre. Finman didn't get this right as the dissolved volume isn't the sum of the parts, and the solutions are measured by volume not weight.

You have three options:

1) Use it as intended by diluting to 1 litre, it is not so bad and better than not treating.

2) Make a 4.5% solution, probably the most popular concentration in the UK. You have 500 mls solution, carrying 60g oxalic and 300g sugar. We're heading for 4.5% in 50% syrup (which some call 3.2% of oxalic acid given that the crystals are oxalic acid dihydrate).

To get the acid right, the 60g of oxalic needs to be diluted (eventually) into 1.33 litres.

You currently have 300g sugar and you'll need this supplemented with about 600g sugar to make this roughly a 1:1 syrup.

Take your 500 mls, add the sugar, warm to dissolve as much as you can, top up with warm water, keep stirring to get all to dissolve, and you're done. You now have 1.33 litres, enough for around 40-50 hives. Assuming that you don't have that number, you could try freezing the left-overs in useful amounts as I don't think it will keep for a year in the fridge. Once it discolours it is done. I never try to keep it from year to year as making it from scratch is so cheap.

3) Go with Finman's (later) suggestion of a 3.5% solution, but not his recipe. Some use this concentration successfully.

OK, you have 500 mls carrying 60g oxalic acid and 300g sugar.

To get the acid right, the 60g of oxalic needs to be diluted (eventually) into 1.714 litres.

You currently have 300g sugar and you'll need this supplemented with about 720g sugar to get a 1:1 syrup.

Take your 500 mls, add the sugar, warm to dissolve as much as possible, top up with warm water, keep stirring to dissolve fully and you're done. You now have 1.714 litres, enough for around 50-60 hives.

It is clear that you don't need to be precise as 3.5%, 4.5% and 6% all work. Constructive criticism welcome. Yes, I know it would be simpler for folk to buy the crystals and make a small amount from scratch.

A comment on the labelling: it says 'stable at a temperature between 10 and 25C' and gives a best before date of Dec 2011. I find that hard to believe.

all the best

Gavin

 

[Finman]

.
Gavin, where you got volume percents.

If you have 6% oxalic acid, it must be weight. You cannot make volume from powder.

If you have 30% sugar, it must weight.

Water is same as volume and as weight.

*llllllll

is it easier to throw away that bottle and go to the shop and bye a balance and oxalic acid.


What in the h*.* it is so difficult. I have studied chemistry in university but i did not understand the Gavin system.

Percent sum is not 100% ? What it is?

 

[gavin]

If you dissolve 1kg sucrose in 1 litre water you get a volume of about 1600 mls (with a density well above 1, the usual value for water). That's why the usual recipe works:

1 litre water + 1 kg sugar + 75g oxalic acid = 4.5% (w/v) solution of oxalic acid.

all the best

Gavin

 

[Finman]

.
Gavin.

1 litre water is 1 kg water. And why you use 1 litre. Its is for 40 hives.


The inventors of tricklig get 3,5% from your formula.

You just made a wrong calculation.

 

[gavin]

Oxalic acid dihydrate - 126.1 g mol-1
Oxalic acid anhydrous - 90.0 g mol-1

So a 4.5% (w/v) concentration of the dihydrate crystals is the same as a 3.2% (w/v) solution of anhydrous oxalic acid, not a 3.5% solution.

The 3.5% (w/v) solution you referred to before was also a solution of oxalic acid dihydrate - a weaker solution that some prefer for their Varroa treatment.

The concentration is expressed as the amount in a given volume of syrup. Adding a weight of sugar to a volume of water conserves the weight but not the volume.

This is getting repetitive now, for which I apologise ...

Gavin

 

[Finman]

.
Who needs your alternative mole calculations?

Is it enough that folks can doit one right way?

 

[Busy Bee]

I am really sorry lads but after reading your thread I think I need to go to university. Most of us are simply folk and need very basic instruction. could someone work it out as most dosen't have digital scales etc etc etc.


Thank

busy Bee

 

[RoofTops]

If you don't have digital scales or a set of good weights buy it ready made but making your own is easy - I've just mixed 500g sugar, 500g water and 37.5g oxalic acid - the stuff which comes as crystals and is the dihydrate form, which I think is the only one you get from the common sources. Weighing 37.5g was a bit of a guess, I measured out 37g then added a bit to make 38g and then took a bit away. The bees aren't going to die if you are the odd gram out.

 

[Finman]

I am really sorry lads but after reading your thread I think I need to go to university. Most of us are simply folk and need very basic instruction. could someone work it out as most dosen't have digital scales etc etc etc.


Thank

busy Bee

keep bees well and keep extractor run busy. If you get extra 10 pound, bye a scale.

 

[jimbeekeeper]

If you don't have digital scales or a set of good weights buy it ready made but making your own is easy - I've just mixed 500g sugar, 500g water and 37.5g oxalic acid - the stuff which comes as crystals and is the dihydrate form, which I think is the only one you get from the common sources. Weighing 37.5g was a bit of a guess, I measured out 37g then added a bit to make 38g and then took a bit away. The bees aren't going to die if you are the odd gram out.

But for about 5 hives, we are back round again to the more sensible amounts of

100g sugar , 100mls water and 7.5g OA

Its simples.

Or just buy it ready made.