It's really easy to do. All I do is get a large freezer bag, coffee cup, half cup of salt and one fourth cup of water. I take the salt and put it into the coffee cup then add the water and stir it up tell it's almost like a wet sand. Then I put the cup into the bag and I add the hydrometer. All you have to do after that is seal the bag and let it sit for about 8 to 12 hours and the reading on it should be at 75%. Mine usually read around 72 or 73 percent so from there I know how to gauge it by just adding 2 or 3. I hope that helps you out.That would be great!
I am going back to the pet store near the office tomorrow on my lunch break and get the non-digital one.
Hopefully on Thursday I can find a digital one.
I would love some help calibrating it, no clue where to start.