Confused about soda ash with Randy's recipe #1

[Djmac]

Hi all,

Its my first attempt at dosing using Randy's recipe #1, and I've purchased all the raw materials from a LFS here in australia.

Calcium carbonate was straight forward (500g) in 3.8 litres of RODI.

My problem was with the alk part of recipe. I purchased pre baked soda-ash:

100% Reef Safe Soda Ash/pH+ Supplement 1kg

100% Reef Safe Soda Ash/pH+ Supplement 1kg - 100% Reef Safe

www.100percentreefsafe.com.au

Their instructions only refer to baking baking soda (ie not what I purchased), and when I asked how to mix the soda ash they said just use the same amount (594g).

Trawling the forums I uncovered this seeming conflicting info:
- 2 + 1/2 cups baking soda is roughtly 2 cups after baking
- 375g as the recommended weight for soda ash in the recipe

I'm sure I've missed something simple here. But by volume 2 cups of soda ash (for the product I received at least) is well over 500g.

Any help is appreciated...

Cheers
Dave

 

[Dburr1014]

Hi all,

Its my first attempt at dosing using Randy's recipe #1, and I've purchased all the raw materials from a LFS here in australia.

Calcium carbonate was straight forward (500g) in 3.8 litres of RODI.

My problem was with the alk part of recipe. I purchased pre baked soda-ash:

100% Reef Safe Soda Ash/pH+ Supplement 1kg

100% Reef Safe Soda Ash/pH+ Supplement 1kg - 100% Reef Safe

www.100percentreefsafe.com.au

Their instructions only refer to baking baking soda (ie not what I purchased), and when I asked how to mix the soda ash they said just use the same amount (594g).

Trawling the forums I uncovered this seeming conflicting info:
- 2 + 1/2 cups baking soda is roughtly 2 cups after baking
- 375g as the recommended weight for soda ash in the recipe

I'm sure I've missed something simple here. But by volume 2 cups of soda ash (for the product I received at least) is well over 500g.

Any help is appreciated...

Cheers
Dave

From what I remember...
2.5 cups soda then bake it. What it is after baking doesn't matter.
I would do 375g. You can always modify the dose after.
Maybe @RandyHolmes-Farley can answer. It is his recipe.

 

[Gtinnel]

I’ve always started with with baking soda that I bake to change to soda ash. I know it loses weight but I never measured how much it weighs after baking it.
According to Bulk Reef Supply’s site you mix 381 grams of soda ash to make a gallon of solution. I would use what their site says and use the 381g. I believe their directions are based off of Randy’s recipe.

 

[Randy Holmes-Farley]

If you don't want to bake baking soda yourself, then using 375 g of washing soda in the recipe intended for baked baking soda.

Not sure why BRS says a higher value. Perhaps they are accounting for moisture in their product.

An Improved Do-it-Yourself Two-Part Calcium and Alkalinity Supplement System by Randy Holmes-Farley - Reefkeeping.com

 

[Djmac]

Thanks everyone for the help. I decided to head down to the supermarket and grabbed some McKenzies bi-carb soda. Sure enough cooked 595g down to 378g, close enough for me.

Im still unsure what the soda ash I purchased was, I decided not to use it without a way to verify. 1kg of the bi-carb was only $2.50 so I'm not too worried.

By volume the cooked bicarb was about 425ml (~1 and 3/4 metric cups), bit hard to measure by volume because it's hard to get it to sit flat.

In contrast 375g of the other stuff was about 275ml (also more granular than the baked baking soda).

 

[Randy Holmes-Farley]

Thanks everyone for the help. I decided to head down to the supermarket and grabbed some McKenzies bi-carb soda. Sure enough cooked 595g down to 378g, close enough for me.

Im still unsure what the soda ash I purchased was, I decided not to use it without a way to verify. 1kg of the bi-carb was only $2.50 so I'm not too worried.

By volume the cooked bicarb was about 425ml (~1 and 3/4 metric cups), bit hard to measure by volume because it's hard to get it to sit flat.

In contrast 375g of the other stuff was about 275ml (also more granular than the baked baking soda).

That's why I devised the recipe the way I did with baked baking soda. Sodium bicarbonate/baking soda is cheap and easy to buy food grade. Washing soda is harder to find with a purity assurance.