Name: Jessica
Message: Hi Paula,


Let me first say, your site is the most informative one I've found, and I'd like to sincerely thank you for providing so much information in such an easy-to-understand format! My question is, however, do you happen to have available a chart for conversions between ounces and grams, liters, quarts, and gallons and that sort of thing? (For example, I'm trying to figure out what size storage container to purchase for holding Urea, and the options for the containers come in 'ounce' sizes.... I'm at a loss trying to figure out how many pounds will fit into each size container!) (Along with other similar 'size' issues I'm having!) Thank you so much for your time!

It's more complicated than you think! Some dry substances weigh three times as much (for example) as an equal volume of water, and thus require only a third the volume, while others are just the reverse, to varying degrees. So, each substance has to be calculated individually.

The fastest way to convert one volume measure to another, or one weight measure to another, is to type into google.com "ounces per gallon" or "ounces per liter" or any such thing. Try it, it's one of their handier innovations. Or, you can search with "ounces liters conversion table" to get something you can print out and use with a calculator.

But then you must multiply by the density of the substance. E.g., "grams per pound" yields 454 grams, so one pound of urea weighs that much. The density of urea is 1.323 grams per cubic centimeter, at room temperature. (One cubic centimeter equals one milliliter (ml), which my non-scientist friends assure me is not necessarily obvious.) So, urea weighs 1.323 times as much as water (one ml of water weighs one gram), and thus requires 454 divided by 1.323 ml, or 343 ml, which is just over one-third of a liter, or 1.45 cups, or a little under fluid twelve ounces, for one pound of urea.

For soda ash, or anhydrous sodium carbonate, the density, or specific gravity, is 2.53, so you can fit more, by weight, into the same size container. ("Crystal" sodium carbonate is the monohydrate, with a specific gravity of only 2.25, so it takes up a little more room.) However, I recommend buying a five-pound container of sodium carbonate from your local swimming pool supply store, or a hardware store that sells swimming pool supplies, in which case you do not need to purchase an additional container in which to store it. The "pH Up" or "pH Increaser" jug comes with a child-resistant cap, which is not a bad thing at all.

For dye, the density varies markedly depending on whether the dye powder has been diluted with sodium sulfate or with Tamol. (See "What is in Procion MX dye powder?") There is no way to tell, and no predicting.

So - you know what the easy way to do this is? If you are buying containers from a dye supplier? Just call them, and ask them what size container you'll need!

<i>Updated January 7, 2008</i>

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