Small Quantities of OA Crystal Mix

[Bead]

I've read most of the previous threads on OA quantities and would just like to check I've got it right before I mix for treatment this week.

Previously, I used the 6% bottled readymix, diluted as per Gavin's and Susbees' suggestion. Ditched the unused solution as it had changed colour by this year. I have a new container of crystals marked Oxalic Acid (doesn't say whether it is dihydrate or whatever)but it's distributed by that Italian firm Enolapi.

As I lost my second colony a month ago, I only need enough for one hive on brood and a half, and I understand that the maximum quantity is 50ml for the whole hive, treating the top box only rather than opening up the cluster.

So, to get enough mixture would I be right in using 3.5g OA crystals with 50ml water and 50g sugar?

 

[Finman]

So, to get enough mixture would I be right in using 3.5g OA crystals with 50ml water and 50g sugar?

It is very good.
and you may measure oxalic acid accurate enough.

 

[masterBK]

If you are measuring out such small quantities I suggest that it is easier to weigh 50g of water using a digital balance that trying to measure out 50mls of water (unless you have a 50ml syringe)

 

[alanf]

to get enough mixture would I be right in using 3.5g OA crystals with 50ml water and 50g sugar?

The oxalic supplied in the plastic bags by Enolapi through CWJ0nes and others is dihydrate. Anhydrous is rare and only really available in small packs from lab supply companies.

The usually quoted proportions are 1 litre of water, 1Kg of sugar, 75g of oxalic dihydrate crystals. So for 2 or 3 hives, 100ml water, 100g sugar, 7,5g oxalic. For one hive you could reduce the mix to 50ml water, 50g sugar and 3.75g oxalic.

3.5g is close enough to make little difference, it's really a question of how accurately you can weigh it. As a guide, a new 20p coin weighs 5g, a 1p coin weighs 3.56g. And as MBK suggests, weighing is more accurate at this quantity. You could try using the tare function on a digital scale, add 3.75g oxalic to a container, then 50g of sugar, then 50g of warm water.

 

[Bead]

Many thanks, all, for the advice.

 

[dclewis]

In my opinion OA is so cheap that its more sensible to make a larger quantity up than needed so that your ability to weigh the OA accurately will not impair the final strength. Go for something like 200g/200ml plus 15g OA and you have a chance of getting something near the strength required unless of course you have realy accurate scales. Dispose of what you don't use and make up more again next year.