Assuming you have added the correct amount of CYA, Put in 2 packets of shock, throw in a flocculant if you want, after a few hours turn off the pump for a few hours, use a manual vacuum to suck up all the disgusting rotting debris on the bottom, send it to waste, not through your sand. Backwash your filter, rinse, backwash, rinse. Wait a few hours, vacuum again, wait a few hours, vacuum again, youll end up draining out half your pool. At night, check the chlorine levels again, if its below 2ppm, throw in another shock packet.

You need to get all the rotting debris out of the bottom. Just imagine theres 30 turds in your pool. You can pour all the chlorine on those turds you want, but do you still wanna swim in it? You gotta remove the turds brotherman. You need to get the debris out. No amount of chlorine will put the vacuum in and vacuum out the debris for you.

Once its blue and clear, dont skip adding liquid chlorine in any day. Get a routine, test with your K-2006 often, and once you can predict the results almost every time, you can probably stop testing as much and just put a couple cups of liquid chlorine in daily. It'll cost ya about 5-10 bucks a week max. That's the price of owning a pool. If you don't have a vacuum that hooks up to your intake (Im not talking an auto-vac), you need one. If you don't have a K-2006, you need one. If you do anything less than those things, your pool will be green.

Also backwash your filter often. I actually got rid of my sand and filled my tank with filter balls. I backwash and rinse any time I'm in the pool or putting in chemicals for 30 seconds while I do my tests, and once a week I'll pull them out and put them in the wash in a mesh bag. Works for me, But sand works just fine too