Varrox under OMF Floor ? dose 1.0g or 1.5g ?

[einsteinagogo]

Okay, so I've got my Varrox, got my OA, have a plan, have my replacement stainless steel floors, to replace the correx inspection boards, and will treat hives this weekend, weather and temperature depending, above 4 degrees C.

Question, dose 1g, should this be increased to 1.5g for under the OMG floor ?

Opinions ?

Also, currently on bb on top of super, should this still be 1g dose of OA crystals.

 

[Erichalfbee]

That's what I plan to do next time I do mine; 0.5g more than the varrox recommendation and 0.5g more for an extra box.

 

[einsteinagogo]

That's what I plan to do next time I do mine; 0.5g more than the varrox recommendation and 0.5g more for an extra box.

I'll weight out 1.5g.

Thanks

 

[Apple]

I have been using 2g
OA is not that expensive
and by vaporising there are no tricky chemistry, like working out if the OA is anhydride, dihydride and how much water or sugar to add.

WARNING !
DO NOT ADD SUGAR TO THE OA IF VAPORISING !!!


James

 

[sussexbaker]

At LASI they recommended 2.5g as the sweet spot, though I can't recall how many boxes that was for.

 

[einsteinagogo]

I have been using 2g
OA is not that expensive
and by vaporising there are no tricky chemistry, like working out if the OA is anhydride, dihydride and how much water or sugar to add.

WARNING !
DO NOT ADD SUGAR TO THE OA IF VAPORISING !!!


James

Yes, I'll not add the sugar!

I'd spotted that one, but thanks for warning!

Andy

 

[MuswellMetro]

At LASI they recommended 2.5g as the sweet spot, though I can't recall how many boxes that was for.

Husan of LASI said 2.25g to us and thats on their langstroths not a 14x8 national

 

[einsteinagogo]

Husan of LASI said 2.25g to us and thats on their langstroths not a 14x8 national

so is this 2.25g based on the volume of a langstroth?

so could be re-calculated for a national ? (if applicable!) or is it not that simple a calculation?

 

[Hivemaker.]

I have been using 2g

I use 2g in the standard national single broods, and 3g in the doubles... have used 4g, 5g and 6g with no observed harm to the bees or brood, i prefer to treat from the top in the double broods, have never treated from below a mesh floor, but knowing how fast it settles on every surface i think a lot would settle on the large area of a mesh floor, so more oxalic would be needed.

 

[MuswellMetro]

so is this 2.25g based on the volume of a langstroth?

so could be re-calculated for a national ? (if applicable!) or is it not that simple a calculation?

yes a langstoth, i used 2,25g under the mesh in my 14x12 with good effect and 1.75g on a 14x8 national based on volume adjustment

varrox say 2g for a dadanrt and 1g for a small swiss box (whatever size that might be) but lasi said some loss of effiency through mesh so extra needed if under mesh but less bees get fried that way

 

[Arfermo]

yes a langstoth, i used 2,25g under the mesh in my 14x12 with good effect and 1.75g on a 14x8 national based on volume adjustment
varrox say 2g for a dadanrt and 1g for a small swiss box (whatever size that might be) but lasi said some loss of effiency through mesh so extra needed if under mesh but less bees get fried that way

Old adage - rules are for guidance of wise men and the obedience of fools. Thus do whatever seems sensible and do not pay too much attention to what the Varrox instructions say as they are probably covering their backs. Agree with Hivemaker. I never use less than 2.5 gr, (difficult to be precise about it anyway) whether single, double BB or in between. And then I treat more than once if necessary and never seen any ill effects other than on the little bar-stewards. The one extra I do advise to ensure full sublimation is to press the crystals well down into the corners of the Varrox pan with one fat thumb if you have such.

 

[Nige.Coll]

I use 2g in the standard national single broods, and 3g in the doubles... have used 4g, 5g and 6g with no observed harm to the bees or brood, i prefer to treat from the top in the double broods, have never treated from below a mesh floor, but knowing how fast it settles on every surface i think a lot would settle on the large area of a mesh floor, so more oxalic would be needed.

Some does recrystallize on the cold mesh. I've noticed a small pile of it on the inspection board when checking the drop after treatment.

When I treat through the OMF it seems to work better with about 3g on single national brood. That's going on the noise from the bees and the drop after treatment.

 

[midnight sun]

I use 2g in the standard national single broods, and 3g in the doubles... have used 4g, 5g and 6g with no observed harm to the bees or brood, i prefer to treat from the top in the double broods, have never treated from below a mesh floor, but knowing how fast it settles on every surface i think a lot would settle on the large area of a mesh floor, so more oxalic would be needed.

I treat from under the floor and found that if you place the Varrox on a sheet at inspection board height, then you get crystals condensing on the underside of the mesh. However, if you use a 'shim' of some sorts to raise the 'cup' up to almost touching the mesh, I find that the heat from the 'cup' tends to be hot enough to prevent this more or less. (there is a fraction of residue compared to no 'shim') Hivemaker knows his stuff, so follow his advice on dose if you wish, as the bees will come to no harm as he says, with the extra Oxalic.(normally 1g according to the official instructions)
He has done 'trials' on this with his own bees.
I use stainless mash floors by the way.
Hope this is useful

 

[Jimmys Mum]

I treat from under the floor and found that if you place the Varrox on a sheet at inspection board height, then you get crystals condensing on the underside of the mesh. However, if you use a 'shim' of some sorts to raise the 'cup' up to almost touching the mesh, I find that the heat from the 'cup' tends to be hot enough to prevent this more or less. (there is a fraction of residue compared to no 'shim') Hivemaker knows his stuff, so follow his advice on dose if you wish, as the bees will come to no harm as he says, with the extra Oxalic.(normally 1g according to the official instructions)
He has done 'trials' on this with his own bees.
I use stainless mash floors by the way.
Hope this is useful

Thanks for this practical advice, I will try raising the varrox pan a little higher as I had significant crystals condensing on the mesh.

 

[Erichalfbee]

Thanks for this practical advice

Yes, thanks from me too.
I have a soldering mat which should do the trick

 

[midnight sun]

Sorry, forgot to mention before in previous post. I add about 15 seconds onto the 'heat up' time as it helps get rid of all the Oxalic in the pan as I found this helped.

 

[Jimy Dee]

I have a very scientific approach - I simply add a level(ish) tea spoon of OA to my vapouriser per hive and the bees have not been adversely affected (no bee kill) but plenty of the enemy nailed.
When I got my vapouriser I did a dry run out in the open by putting a level teaspoon of the AO into it and turning it on, and I then timed how long it took for the whole lot to vapourise. That dictated how long it took to do the job.

 

[midnight sun]

I have a very scientific approach - I simply add a level(ish) tea spoon of OA to my vapouriser per hive and the bees have not been adversely affected (no bee kill) but plenty of the enemy nailed.
When I got my vapouriser I did a dry run out in the open by putting a level teaspoon of the AO into it and turning it on, and I then timed how long it took for the whole lot to vapourise. That dictated how long it took to do the job.

Out of curiosity Jimy dee, how long did it take for complete sublimation if you please?

 

[Heather]

I was vaporising and bought the small container of OA dihydrate, that came with a tiny plastic spoon. P.....s said 1 scoop is all required, and I followed instructions. but after 24 hrs there is either no drop or minimal (10 - 15 varroa) which makes me think this was inadequate..
Any thoughts?
Doubt my bees THAT clean.

My treatment was completed within 1 minute.

 

[Nige.Coll]

I was vaporising and bought the small container of OA dihydrate, that came with a tiny plastic spoon. P.....s said 1 scoop is all required, and I followed instructions. but after 24 hrs there is either no drop or minimal (10 - 15 varroa) which makes me think this was inadequate..
Any thoughts?
Doubt my bees THAT clean.

My treatment was completed within 1 minute.

The tiny spoon is around 1 gram.