Acetic Acid Treatment

[JonnyPicklechin]

I piled 3 columns of brood boxes, 4 high boxes on each and sealed them. Left in the garage with 500ml of 80% acetic acid on top of each, in turn, in reasonably wide ceramic bowls.
The garage is not heated so I put two electric filament heaters on full time but with this cold weather im not certain the ambient was much above 13 to 15 deg C at night.
I checked this morning after 7 days and there looks like still quite a lot of the acid left in the bowls.
Will the treatment have had any sterilisation effect at all?
I dont mind leaving the treatment running longer.
Or must I find a way to raise the temperature to ensure better evaporation action to assure efficacy?

 

[jeff33]

I had the same conundrum, in the end as I couldn't find a solution I gave up on the idea of acetic acid and use sulphur instead. I raised the query a few weeks back and others have commented that it eventually evaporates but the current temps are rather cold so not sure what the minimum should be.

 

[Curly green finger's]

I had the same conundrum, in the end as I couldn't find a solution I gave up on the idea of acetic acid and use sulphur instead. I raised the query a few weeks back and others have commented that it eventually evaporates but the current temps are rather cold so not sure what the minimum should be.

I agree with Jeff, I've been recommended to use sulfur bombs and will be using them instead of acetic acid.

 

[Curly green finger's]

I dont know why I've not used them before, we use them in the tunnel and chicken shed.

 

[JonnyPicklechin]

Cheers chaps...So I would have the same set up? Can you instruct me what to get and how to handle? Assume I'm dumb with sulphur bombs which is probably the safest position to be.

 

[drex]

A more expensive option but Thornes sell sulphur impregnated strips and a burner to put them in. Is what I use.

 

[JonnyPicklechin]

cheers Drex...I can see them. Not too expensive. Just put inside an empty brood on top. Does a signal "burn" sterilise against nosema spores? None of this waiting a week business?

 

[drex]

I don't think it kills nosema spores, but I might be wrong. I use it for wax moth prevention.
Nosema is endemic. I have never bothered with acetic as it is too much faffing and not had any significant clinical nosema problem . The only sure fire way to diagnose nosema is by microscope, which I have.
Just done a Google. No mention of sulphur killing nosema but 10% bleach does.

 

[Erichalfbee]

I don't think it kills nosema spores, but I might be wrong. I use it for wax moth prevention.
Nosema is endemic. I have never bothered with acetic as it is too much faffing and not had any significant clinical nosema problem . The only sure fire way to diagnose nosema is by microscope, which I have.
Just done a Google. No mention of sulphur killing nosema but 10% bleach does.

Randy OliverQuick Squash is a really easy method.

 

[jeff33]

I don't think it kills nosema spores, but I might be wrong. I use it for wax moth prevention.
Nosema is endemic. I have never bothered with acetic as it is too much faffing and not had any significant clinical nosema problem . The only sure fire way to diagnose nosema is by microscope, which I have.
Just done a Google. No mention of sulphur killing nosema but 10% bleach does.

Quite right, it doesn't, I just use for wax moth and got the thornes set-up.

 

[JonnyPicklechin]

Its odd...all the UK based Acetic acid sterilisation instructions make no mention of assuring a good ambient temperature for effective evaporation.

 

[Hebeegeebee]

I use plastic takaway trays for the acid and leave paper towels hanging out of the trays on two sides so the acetic acid wicks up and over and is evaporated in a week. Completed a few large stacks of brood boxes and supers like that over the past few weeks.
Don't get a lung-full though!

 

[Bazzer]

I piled 3 columns of brood boxes, 4 high boxes on each and sealed them. Left in the garage with 500ml of 80% acetic acid on top of each, in turn, in reasonably wide ceramic bowls.
The garage is not heated so I put two electric filament heaters on full time but with this cold weather im not certain the ambient was much above 13 to 15 deg C at night.
I checked this morning after 7 days and there looks like still quite a lot of the acid left in the bowls.
Will the treatment have had any sterilisation effect at all?
I dont mind leaving the treatment running longer.
Or must I find a way to raise the temperature to ensure better evaporation action to assure efficacy?

The amount of acetic acid that has been recommended by NBU etc is completely bonkers. To achieve a saturated vapour presssure of acetic acid within a brood box at say 15 degC requires less than 2 ml. Thus, if you have 4 boxes stacked up and well sealed then 10-15 ml is enough to do the job fine. It is easy to show that this is working by putting a panel pin on top of one of the frames in each box. This will rust showing it has been exposed to the acetic acid vapour. If anyone on here has any influence with the NBU please could you get them to update their sheet. Vast amounts of a fairly nasty chemical must be getting unecessarily bought, handled and disposed of.

 

[Nige.Coll]

It doesn't evaporate well from a bowl.
I use some pads that were for formic acid treatments.

 

[Sutty]

The amount of acetic acid that has been recommended by NBU etc is completely bonkers. To achieve a saturated vapour presssure of acetic acid within a brood box at say 15 degC requires less than 2 ml. Thus, if you have 4 boxes stacked up and well sealed then 10-15 ml is enough to do the job fine. It is easy to show that this is working by putting a panel pin on top of one of the frames in each box. This will rust showing it has been exposed to the acetic acid vapour. If anyone on here has any influence with the NBU please could you get them to update their sheet. Vast amounts of a fairly nasty chemical must be getting unecessarily bought, handled and disposed of.

I'm a bit of a geek, I believe you entirely, but would love the figures you're working from.

 

[Finman]

I don't think it kills nosema spores, but I might be wrong. I use it for wax moth prevention.
Nosema is endemic. I have never bothered with acetic as it is too much faffing and not had any significant clinical nosema problem . The only sure fire way to diagnose nosema is by microscope, which I have.
Just done a Google. No mention of sulphur killing nosema but 10% bleach does.

And iving spores stay in hives. Nothing kills them there.

 

[elainemary]

I tried a while ago to find out how long nosema spores lasted for on combs ... think I read 4 months but it was a bit woolly..anyone know?
When I last made up some slides I found a few spores from one hive. I left the slides with coverslip on and the spores disappeared overnight, spoke to a microscopist who said they desiccate v quickly out of a hive, so that made me think empty frames are less of a risk. But what about those with stores in, how long are the spores active for? I heard Lyfa Davis on a talk recently, say sterilise capped stores and you can feed back to the bees but not uncapped. She didn’t say why...again anyone know the answer to this?

 

[jeff33]

No idea.
I work on the principal that if a hive has a bad case of nosema it is moved away from other hives to avoid drifting, frames and boxes are not mixed with others and depending on spoilage, frames are burnt or boiled in a bleach solution.

 

[bazdmoore]

I piled 3 columns of brood boxes, 4 high boxes on each and sealed them. Left in the garage with 500ml of 80% acetic acid on top of each, in turn, in reasonably wide ceramic bowls.
The garage is not heated so I put two electric filament heaters on full time but with this cold weather im not certain the ambient was much above 13 to 15 deg C at night.
I checked this morning after 7 days and there looks like still quite a lot of the acid left in the bowls.
Will the treatment have had any sterilisation effect at all?
I dont mind leaving the treatment running longer.
Or must I find a way to raise the temperature to ensure better evaporation action to assure efficacy?

The quantities recommended are completely bonkers from a physical chemistry point of view. At a temperature of say 15C only about 2ml of acetic acid are required to reach the saturated vapour pressure in a sealed system

I'm a bit of a geek, I believe you entirely, but would love the figures

 

[bazdmoore]

I'm a bit of a geek, I believe you entirely, but would love the figures you're working from.

Basically vapour pressure of acetic acid is around 8.4mmHg at 15°C
Coverting to atm = 8.4/750 = 0.0112 atm
Deep brood box has volume of 50 litre
so using PV=nRT , number of moles of acetic acid needed = 0.0112 ×50/0.0821×288= 0.024 moles
Mol wt acetic acid = 60 60×0.024 = 1.4 g
Using 80% acetic so need slightly more - 1.4/0.8 = 1.77g
Density about 1 so 1.77ml needed to achieve saturation in a deep brood box. Some will adsorb onto comb but if system well sealed you certainly dont need more than 5ml which is way less than the 120ml recommended