Hi Katskan,

Well, I'd say you need about one and one third ounces of citric acid to a gallon of water. Here's the way I figured it:

One US gallon of water weighs about 8.345 pounds (depending on the temperature).

So:

A) 1 PPM = 8.345 pounds per million gallons of water.

B) Converting to ounces: 1 PPM = 133.52 ounces per million gallons of water.

C) Bringing it down to one gallon: 1 PPM = .00013352 ounces per gallon.

D) Going from 1 PPM to 10,000 PPM: 10,000 PPM = 1.3352 ounces per gallon.

Hope this helps.

Hello Art and thanks for the fast reply. Much appreciated.

So if I understand your calculations, I'd need roughly 3 US tablespoons of citric acid powder per US gallon of water to make the 10,000 PPM solution. Sound about right?

Thanks again.

Of course, to be perfectly accurate, it would depend on how much a tablespoon full of citric acid weighed. However, I'm sure the 3 tablespoons would be pretty close; that's probably what I'd use.

Thanks very much Art. Although the 3 tablespoons of citric acid per gallon of water might not be exactly 10,000 PPM I think it should be close enough for use on seeds with very hard seed coats.

Thanks again for your time.

I just heard about citric acid soak for germination for seeds. On the container, it says for sprouting seeds. My friend tried it on some almost impossible to germinate silky camellias and the seeds are germinating about 2 days. I would like to try it on some daylily seeds - has anyone ever soaked daylily seeds in this? Can anyone provide other information on this? I normally soak mine in a hydrogen peroxide/distilled water mix. Thanks for any advice......