Is my yeast starter ruined?

Ok, so I made my first yeast starter last night for a brew I am doing tomorrow.
I followed the instructions here but somehow missed one step.
https://www.homebrewtalk.com/f39/how-make-yeast-starter-pictorial-76101/

I didnt add more water to the 800 ml. I simple used 2 cups water, 1/2 cup DME and boiled for 10 min. Cooled and added the yeast. We have been shaking as often as possible since last night.

The question is can I just add some additional water at this point or should I not worry?

Thanks
Robert

I'd say you are good to go. Looks like you followed those directions in the diagram pretty well.

1 cup looks like it is 237 ml so, 2 x 237 is 474 ml. The instructions show to add water up to the 800 ml mark. Do I have enough liquid in my starter at this point for goo dyeast growth? Can I just add additional water at this point without any worry of contamination?

I think what you are reading is referring to making a half strength starter. You followed directions for a normal strength starter so you are good.

Your starter may be a little stronger than a 1.020 wort but the yeast will be fine, I would not worry about the risk of contamination by adding more water, even if you boiled and cooled it, just leave it.

I would recommend though you go to http://www.yeastcalc.com and plug in your numbers to find your proper pitching rate and be sure you don't need to step up what you got.