weight vs. volume

[waterbear]

1 oz dry weight is 1/8 cup or 2 tblsp.

This is not always true. particularly with pool chemicals that have different densities. It is a rough approximation at best but if you want to convert a weight measure to a volume measure you will need to do it separately for each item, based on it's density.
A pound of DE powder takes up a lot more space than a pound of trichlor tabs.
For example 1 tablespoon of steel ball bearings and 1 tablespoon of rice krispies each would weigh 1/2 oz by the formula above but we don't even need to measure and then weigh them to know this is not going to be true!

There is no hard and fast rule that will successfully convert a volume measurement to a weight measurement or vice versa.

However, an inexpensive kitchen or diet scale is excellent for weighing out pool chemicals.

[chem geek]

Examples of densities of some pool chemicals are in this thread where the second number (bulk) is the relevant one. You can see that densities vary from 0.837 for calcium chloride dihydrate to 1.44 for dry acid. The one ounce weight to one ounce (1/8th cup) volume approximation is only correct when the density is 0.959 g/ml.

Sorry for the bad formatting...the "CODE" formatting on this forum no longer works (that's used to force a fixed space font which is good for lining up columns).

[AnnaK]

Confused yet, purplegirl?

[sturev]

I wonder if the weights make a difference when she adds them to her green pool that's filled with iron? Gotta be heavier!

[purplegirl]

sturev are you making fun of my green pool

I would probably be confused AnnaK if I didn't have a scale, but since I do I'm not going to worry about all the rest, I'll just weigh everything out.

But thanks to everyone for the info. I never realized having a pool was so much work

[Watermom]

Your pool won't always be so much work. Once you have done this for awhile, it will become routine and will be easy. I typically spend less than 5 minutes each day on my pool. That is it. (Other than throwing in the Wanda the Whale vacuum a couple of times per week. But, then she does the work, not me!)

[CarlD]

'Mom is right (she is pretty much 99.99% of the time). None of the mods spends a great deal of time maintaining our pools--nor do most of our members (at least the active ones). Our methods are geared to being:

1) Effective
2) Simple
3) Cheap
4) Easy

But you do have to be consistent.

Actually, most of us spend far more time on PF than we do maintaining our own pools!

[AnnaK]

I would probably be confused AnnaK if I didn't have a scale, but since I do I'm not going to worry about all the rest, I'll just weigh everything out.

That's what I do. I moved my old kitchen scale into the pool house and weigh the solids. Having grown up in a "metric" country I'm more comfortable using a scale for dry ingredients rather than cup or spoon measures.