Hi Guys,
I have an impossible question for you, how much weight change is there when a dry powder gets damp? For example I have a pot of bicarb that has gone soft due to damp getting in. How much has that changed the weight of it.
thanks
Simon
Damp powders
Moderators: B.Scott, vippymini, Gazza, Manky Sanke
Re: Damp powders
Hi Simon
I wouldn't worry you would be hard pressed to over dose on bicarb with a little damp in the product.
Regards geoff
I wouldn't worry you would be hard pressed to over dose on bicarb with a little damp in the product.
Regards geoff
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Manky Sanke
- Site Admin
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Re: Damp powders
Pah phooey, that ain't an impossible question, Simon,
It's a simple matter of molecular weights.
As Geoff says, it's almost impossible to overdose with sodium bicarbonate but since it will raise the KH and possibly the pH there are sensible limits to the amount that should be added to a pond at any one time.
If the pH changes by more than about 0.2 per day or if you increase the KH by more than about 20 mg/L per day, it can cause koi to become stressed because it interferes with their blood chemistry and they need time to adjust. This is very unlikely to cause long term harm, but it's bad practise to do anything to a koi that causes stress.
A while ago, I did the molecular arithmetic to calculate just how much sodium bicarbonate is needed to raise KH by 20 mg/L. It works out to 129 gm per 1,000 gallons. So, for easy numbers, I have been recommending that 100 grams per 1,000 gallons is the most that should be added per day. This builds in a good safety margin to allow for inaccurate measuring.
Having said all that, if you are adding sodium bicarbonate at a rate of 100 grams per thousand, any inaccuracy in measuring the weight that might be caused by damp will be well within the safety limit. Also, the damp will probabably increase the weight of the powder, so 100 grams of damp powder would probably only contain 90 odd grams of sodium bicarbonate anyway.
It would be better to keep the powder dry in future but using up the damp powder won't cause any harm.
It's a simple matter of molecular weights.
As Geoff says, it's almost impossible to overdose with sodium bicarbonate but since it will raise the KH and possibly the pH there are sensible limits to the amount that should be added to a pond at any one time.
If the pH changes by more than about 0.2 per day or if you increase the KH by more than about 20 mg/L per day, it can cause koi to become stressed because it interferes with their blood chemistry and they need time to adjust. This is very unlikely to cause long term harm, but it's bad practise to do anything to a koi that causes stress.
A while ago, I did the molecular arithmetic to calculate just how much sodium bicarbonate is needed to raise KH by 20 mg/L. It works out to 129 gm per 1,000 gallons. So, for easy numbers, I have been recommending that 100 grams per 1,000 gallons is the most that should be added per day. This builds in a good safety margin to allow for inaccurate measuring.
Having said all that, if you are adding sodium bicarbonate at a rate of 100 grams per thousand, any inaccuracy in measuring the weight that might be caused by damp will be well within the safety limit. Also, the damp will probabably increase the weight of the powder, so 100 grams of damp powder would probably only contain 90 odd grams of sodium bicarbonate anyway.
It would be better to keep the powder dry in future but using up the damp powder won't cause any harm.