sourdough newbie and king arthur

"if I am constantly discarding half and then adding in 1/2 cup water/1 cup flour, won't it keep getting thicker and thicker?"

1:2 is probably the most common ratio of flour to water for a starter; that gives you 100% hydration, which will produce a starter that is somewhat thicker than pancake batter.  Since you are adding the same ratio of water to flour each time, the consistency will always be the same.

"My question is, how would you recommend pulling this off, getting it going?"

My best answer is: Don't worry about it.  Feed it and leave it on the counter as long as you can before you go to work, then put it in the fridge until you get home.  Take it out and feed it and leave it out until it reaches maximum volume and begins to fall back, then feed it again.  Don't worry about following KA's directions -- it's hard to mess up a starter.

The important thing is when you are ready to use it.  Take it out and feed it by doubling it.  In other words, if it already contains 1/2 a cup of flour, add another 1/2 cup of flour and 1/4 cup of water; when it begins to fall back, add 1 cup flour and 1/2 a cup of water.  If you need still more starter, double it again, always maintaining that 1:2 ratio.

Finally, there is no need to waste so much flour.  After I'm done baking, I keep only one tablespoon of starter, feed it by doubling (approximately, but maintaining the 1:2 ration), and stick it in the fridge.  I then feed it about once a week until I'm ready to bake again, at which point I repeat the process in the previous paragraph.

Once again, don't worry about it.  Messing it up is almost impossible.  Just don't let it get too warm, and don't use water over about 80 degrees.  Oh, yes . . . and don't use Clorox or paint thinner instead of water.

would be in opposition to KA starter.  Any SD starter that works is a good thing and KA starter will work just fine.  Once yours is established say in a month then you can handle it differently and reduce the amount of maintenance and waste.  I keep 100g of rye sour starter in the fridge at 66% hydration (60 g of rye and 40 g of water) and bake with 10-20 g out of it every week - with no maintenance at all   When it gets down to 10- 15 g ( after 2-4 weeks) i refresh it over 3 feedings on the counter back too100g  and into the fridge it goes for  another 3-4 weeks..

Welcome and happy SD baking!

This discipline was recommended to me by Debra Wink, a TFL member, who is widely recognized as the author of:

http://www.thefreshloaf.com/node/10856/pineapple-juice-solution-part-1

http://www.thefreshloaf.com/node/10901/pineapple-juice-solution-part-2

About two years ago she helped me nurse a seed starter, refrigerator stored and fed weekly, that was going south.

With her guidance, after about a dozen days, my starter was healthy and vigorous, once again. I then asked what she recommended my maintenance program should be, with the caveat that baking SD only once a week, and busy with other non-baking projects, realistically, keeping my seed starter in the refrigerator was my best option. Her answer: Since you're making all that good, fresh levain every week simply make a little extra and save it as your next week's seed starter. She went on to say I only needed to save about 20g of seed starter, and could build all I wanted from that small amount.

I already had a levain building discipline that serves me well (I still use it faithfully.) http://www.thefreshloaf.com/node/12766/building-formulaready-levain-starter

I adopted her recommendation, but I save 60g of fresh levain week-to-week. I use 40g of seed starter to initiate building 320g of fresh levain: 250g for my routine SD bake, and another 20g I feed 20g of bread flour (KA) and 20g of water (i.e.1:1:1 ratio) and store it immediately in the refrigerator for the following week. I discard all the remaining seed starter saved from the previous week. I keep my seed starter at 100% hydration, and build most levains at 100% for simplicity. However, it's easy enough to change a levain's hydration, as described in my post cited and many other ways.

I've been following Ms. Wink's recommendation for two years, with 100% consistency in my SD baking results.

Happy baking,

David G

P.S. I've been using KA products for decades. I've been to their baking classes in Norwich, VT and I've used their SD starter. KA is a bit pricey, but has never failed me. In my opinion, they are trustworthy.