Carbonate reducing acids

[SiHoltye]

Should we only as these to cold liquor of the required length? What's wrong with adding them to a small volume then diluting as in whilst the vessel is filling up, and whats wrong with adding them to heated liquor?

[Jim]

I always add my water treatment to a small amount of water (2 x 2lt pop bottles) and spend an hour or two giving them the occasional shake. Once the brewing water is run, I add the contents of the bottles.

[vacant]

AMS can be used in "hot or cold liquor tanks". I can't see why other acids should be different. I believe the reaction is instantaneous but I don't know what level of turbulence (stirring) is required to achieve a complete distribution.

[mabrungard]

The problem with heated water is that if it has much Temporary Hardness, the heating may drive off a portion of the Temporary Hardness (aka: Alkalinity). If you have calculated your acid addition based on the alkalinity of the tap water, then you will likely over dose the water with acid.

Now, if you test the heated water and determine its new alkalinity and use that value to calculate the acid addition, then there is no problem with adding acid to hot water.

[killer]

To expand slightly on Martins comments.... When you heat alkaline water, you precipitate the more soluble Calcium Bicarbonate (CaHCO3) as Calcium carbonate (CaCO3). As such, you could over acidify the liquor as you no longer need as much acid (you've removed much of the alkalinity as a solid).

Adding to a small volume of liquid first is not a problem as long as you add it after you fill the liquor tank - Conc acids such as HCl and H2SO4 can damage metal vessels if added neat. So Jims method above is fine.