I'm not a fan of trying new things with my eggs when I have a great tried and true method.

Here is what I do so that I don't have any guess work:

1. I use a 6 quart iris tub, I put it on a scale to zero the scale out.

2. I put in 500 grams of vermiculite (make sure that is dry vermiculite, the red bags from home depot often have moisture in them, open those bags and dump them into a large tub a week or so before you need it and allow it to air dry).

3. I then add 500 grams of water, just adding water until the scale reaches 1000

4. I then gather up my eggs place them in tub and then put the entire scale back onto the scale. I record this weight right on the tub tag along with the clutch info.

This number, say 1600 grams (500 grams vermiculite, 500 grams water and 600 grams for the eggs). I then have (along with the majority of friends) have egg maintenance Thursdays. We all remember to call each-other on Thursdays to remind each one of us to do our egg maintenance.

This consists of pulling each tub out of the incubator and weighing it. On average in my incubator each tub looses around 20 grams of weight. This is not coming from the vermiculite or the eggs, only thing is the water. I then simply add 20 grams of water, close the tub and don't look at it again until next Thursday.

I do this each week the eggs are cooking up until the last two weeks of incubation where I simply just don't add any more water to allow them to cave in a bit.

Very very simple, 100% accurate unless you cannot multiply by 2 in the beginning when trying to figure out the amount of water to add.

Let me know if you have any questions.