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Coming soon! Handy-dandy tables for determining water and detergent amounts to achieve particular dilutions.

Figuring it Out On Your Own - Some Simple Math[]

To figure out dilutions on your own is quite simple. Don't be intimidated by the math. All that is required is some simple addition, division and multiplication that you can let a calculator do. I am assuming that if you are reading this, the math seems daunting -- so rather than give the general formula, I have provided the steps for figuring things out based on your scenario.

Normally, I use weight for measuring. For water and most detergents, it is reasonable to treat volumes as additive (weight is always additive) but you can't do this with some combinations of liquids since volume is not necessarily additive. Alcohol and water are a combination of liquids where the volumes are not additive.

If you know the total amount that you want to make[]

If you want to find out how much detergent and water you need to make a specific amount of juice with a particular dilution ratio, here is what to you need to do:

  • Write down the amount of juice that you want to make. Let's call that Total Amount.
  • Write down the "parts water" and "parts detergent" as W and D respectively. For example, if you want a 20:1 ratio, W is 20 and D is 1.
  • Write down W + D as Total Parts. For 20:1, Total Parts is 20 + 1 which is 21. A common mistake in calculating ratios is forgetting that a 20:1 solution has 21 parts and not just 20.
  • To find out how much one part is, do this calculation: One Part = Total Amount / Total Parts
  • The amount of detergent you need is One Part times the number of parts of detergent. Normally, this is just One Part. So you don't have to really do any multiplication unless your D number is not one.
  • The amount of water you need is just W times the amount for one part.

An example (gallon). Let's say I want to make one gallon of bubble juice at a 20:1 water:detergent ratio. Total Amount is 128 ounces. Total Parts is 21. One part is 128/21 which is 6.1. The amount of detergent needed is 6.1 ounces. The amount of water is 20 times 6.1 is 121.9. We can round those to 6 ounces detergent and 122 ounces water. FWIW,  I normally do my calculations using grams to reduce the influence of rounding error.

An example (2 liters). The total amount is 2 liters which is 2000 ml. For a 20:1 juice, we have W at 20 and D at 1. So, Total Parts is 21. One part is 2000 divided by 21 which is 95.2. 20 parts is 20 times 95.2 or 1910 ml water. I generally do my measurements by weight and treat 1 ml as being one gram for both water and detergent. 1 ml of water weighs (by definition) precisely one gram. It turns out that 1 ml of detergent also weighs very close to one gram.

Easy ratios. From the point of view of the math, 19:1 and 24:1 lead to neater looking numbers since the total parts are 20 and 25 respectively. So they are often convenient to use.

If you know the amount of water that you are going to use[]

Sometimes, you know the amount of water that you are going to use and just need to know how much detergent to add to it. If the water:detergent ratio has 1 for the detergent part (as in 20:1), you just divide the amount of water by the water's ratio number. For example, if you are using 128 ounces of water (one gallon) and want to make 20:1 juice, divide 128 by 20 which gives you 6.4 ounces. The total amount of juice you will have will be 128 ounces plu 6.4 ounces.

If you know the amount of detergent that you are going to use[]

If you want to know how much water to add to a particular amount of detergent, multiply the amount of detergent by the water's ratio number. For example, if you want to make 20:1 juice and want to use 8 ounces of detergent, multiply 8 by 20 (the water's ratio number) which gives you 160 ounces. The total amount of juice will be 168 (160 ounces water plus 8 ounces detergent).

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