Is that 2,600 or 26,000 gallons? 2,600 seems small to me for an inground pool. This is a key value when it comes to figuring out how much bleach (or acid or baking soda or whatever) to add.

As CarlD said, you aren't going to know how much chlorine to put in there until you know your CYA (Cyanuric Acid aka Stabilizer) level To know that, you need a test kit that tests CYA. Until you get the K-2006 kit in you can get by with an "HTH 6 way test kit" from walmart. They're listed at $22 on the website, but the idea is to get it from the store so you can get it today. Here's a link so you'll know what to look for: http://www.walmart.com/ip/HTH-6-Way-Test-Kit/17043668 There is also an "6 way test STRIP" kit that you do NOT want. You want the kit that uses liquid drops.

Cleaning up a problem like that (assuming it's not black paint chalking off?) takes some time. Time and consistency. If you're going out of town you can't be consistent right now. Honestly I wouldn't waste money starting cleanup until I got back...Unless your town is like mine where it is illegal to have a green pool.

Here's some reading material: http://www.poolsolutions.com/gd/the-...pool-care.html <- read first

Here's some more: http://www.poolsolutions.com/gd/best...ine-chart.html <- read second.

Once you get a test kit that measures CYA, post that number and someone here can help you get started.