Should I feed my yeast starter?

So I'm doing my first yeast starter for an apple wine. My apple wine is sitting with a few camden tablets for 24 hours or so to hopefully take care of any wild yeast, and in the meantime I created a yeast starter using a cup of bottled spring water, 3 tablespoons of orange juice, 1 tablespoon of dextrose, one pack of SN9 wine yeast.

I put it all in a sterilized beer bottle and through on an airlock. The thing was bubbling away within 30 minutes and this morning (about 10 hours later it's just one big bottle of frothy yeast.

My question... I still need to let the camden tablets sit for another 10 hours or so. Is there any risk of my yeast using up all the sugar and starting to die off by the time the camden tablets are done doing there thing? Should I be feeding the yeast starter occasionally to keep it going or is there enough sugar in there to keep things healthy for the total time of 24 hours?

Thanks for any advice anyone might have.

Instead of storing in an air locked bottle, it should be in something open. The yeast need oxygen in addition to sugars to populate. A plastic or ceramic bowl w/ a cloth or paper towel on top works well. As for feeding, stir in a 1/4 to 1/2 cup apple juice every 4-6 hrs. That'll really get the culture going and get them used to the apple sugars they'll be living on.

Oh, okay, I figured that fermenting it just like a normal brew was the way to go. Thanks for the tip. I'll remove the airlock and add a paper towel. Like an idiot I went and threw every last drop of apple juice into the must and then hit it with a camden tablet. Otherwise I would have used apple juice. I have some store bought stuff on hand but it lists (food acid) as an ingredient. Though it says "no preservatives" on the front of the bottle. Any idea if "food acid" is safe or should I just stick with the orange juice/sugar mix?