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- Jan 1, 2018
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- Fernhurst Sussex
- Hive Type
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- Number of Hives
- 40 plus 23 that I maintain for clients.
Indeed!
New equipment these days!!…. I think much of the older research would have been done with the old pan types. Back then it was much faster to trickle.Maybe I am doing it wrong but 4.3min to sublimate 2.5gr? When the gasvap has reached optimum temperature it takes me less than a minute per hive.
The charts presented in the article seem to show that 4g is better than 2g if reducing mite levels is your objective.....David Evans summarised his view of the research regarding OA dosage in November last year (mostly in the part headed "Dosage, again", but there's interesting stuff in the comments too):
Repeated oxalic acid vaporisation - The Apiarist
I'd read it as suggesting that a 4g dose will kill a higher percentage of mites, but it may not be a sufficiently large increase over 2g to make a real difference and that more research is probably required into dosage, timing and probably other variables too (hive volume, perhaps, given that the US recommendation is based on the number of brood boxes).
I'm really not sure that increasing the dosage is giving the anti-vaping brigade that much more ammunition than using a non-approved product or performing repeated applications (even with an approved product) mind...
James
I’m pretty sure I could imagine his response to that"Pete Little (Hivemaker) did some experiments increasing the dose above the recommended levels and found that there were no obvious signs of distressing the bees but ... increasing the dose did not show any improvement over the mite killing"
This is not a controlled experiment, peer reviewed and published in an academic journal. I know because I have looked for it in scientific journals and it has not been published.
I think he'll be looking down and muttering ....he didn't suffer fools lightly. I don't know anyone who had more PRACTICAL experience of sublimating OA ... if his recommedation was for 2.5gms - good enough for me.I’m pretty sure I could imagine his response to that
Interestingly Api-Bioxal is recommended in the article as a once a year treatment (at 2.25g) when vaporising it but....
twice a year when trickling.
To be more scientific on this:Right.... for any beginners reading this and taking any notice of Sean-a's personal opinion. Please note ... the proven and recognised dosage for treatment of varroa by sublimating oxalic acid is 2.5 gms per colony.
There is no benefit from overdosing and none of the manufacturers of authorised OA treatments and those people who have investigated and tested unauthorised treatments recommend using any more than 2.5 gms.
Sean-a is entitled to his personal opinion but please accept that it is just HIS PERSONAL OPINION and should not be followed.
Some other light reading on this attached and below in links.David Evans summarised his view of the research regarding OA dosage in November last year (mostly in the part headed "Dosage, again", but there's interesting stuff in the comments too):
Repeated oxalic acid vaporisation - The Apiarist
I'd read it as suggesting that a 4g dose will kill a higher percentage of mites, but it may not be a sufficiently large increase over 2g to make a real difference and that more research is probably required into dosage, timing and probably other variables too (hive volume, perhaps, given that the US recommendation is based on the number of brood boxes).
I'm really not sure that increasing the dosage is giving the anti-vaping brigade that much more ammunition than using a non-approved product or performing repeated applications (even with an approved product) mind...
James
Thanks..I didn't know what it was calledGland pliers Snap!
Thanks..I didn't know what it was called
really useful thanks thought the point of the measuring spoon supplied by Gasvap was it put the right amount it, why not make it the right size aaaagh. Really great thanks.Using the gasvap 13mm end cap measure spoon OA is approx. 1.15g - 1.3g per level fill if one just scoops up a level loose fill. A compacted fill by tapping the spoon to settle the OA it is 1.55g - 1.6g.
If one uses Api bioxal a level spoon is 1.6 - 1.65g.
A 22mm end feed cap contains 5.5g approx. of OA compacted by tapping it and 6.3g of Apibioxal.
For OA dosing two spoons of the loose fill method is needed or if using Apibioxal 1.5 spoons. If one is tapping and compacting the measure spoon then also 1.5 is the dose for 2.4 - 2.5g of OA.
Better still instead of guessing or over dosing, weigh your own samples to check and get the dose correct.
It's because just about all the bits of the gasvap are made from standard copper fittings ... the 'scoop' is either an 8mm or 10mm copper pipe end cap. The next size up would be 15mm which is too big. Making a bespoke measure that also serves as a pipe cleaner for the nozzle would be prohibitively expensive.really useful thanks thought the point of the measuring spoon supplied by Gasvap was it put the right amount it, why not make it the right size aaaagh. Really great thanks.
we don't need to be spoon fed every last bit of kit do we ?
really useful thanks thought the point of the measuring spoon supplied by Gasvap was it put the right amount it, why not make it the right size aaaagh. Really great thanks.
Even a pan is only 3mins or less to sublimate 2.5g.Maybe I am doing it wrong but 4.3min to sublimate 2.5gr? When the gasvap has reached optimum temperature it takes me less than a minute per hive.
No but useful when you buy it for it to say it is not the correct size for 2.5mg sort of just assumed it was. Thought the designer had worked through that. on a bigger pipe they could have just cut the height down to the right size.It's because just about all the bits of the gasvap are made from standard copper fittings ... the 'scoop' is either an 8mm or 10mm copper pipe end cap. The next size up would be 15mm which is too big. Making a bespoke measure that also serves as a pipe cleaner for the nozzle would be prohibitively expensive.
It ain't rocket science to make your own - a clear plastic tube with a mark to show where the correct weight is .. we don't need to be spoon fed every last bit of kit do we ?
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