First thing you need to do is get some chlorine in there or you'll be amazed at how fast it turns green! I'm assuming your pool's volume is around 18K. In this amount of water, each gallon will add approximately 3ppm of chlorine. Until you get some stabilizer in there, the chlorine will disappear fast. You'll probably need to test and add bleach at least twice and 3x a day is better for the first week and each time, add enough bleach to get back up to 6ppm or so. Also, you'll need to add some CYA, also called cyanuric acid, stabilizer or conditioner.) Aim for an initial amount of about 30-35 ppm. You can always add more if you need it, but the only way to remove it is to drain which you don't want to do. Add it slowly to the skimmer while the pump is running and let your pump run 24/7 for several days. It will take up to a week to totally dissolve in the filter, so don't backwash, test for it or add more for a week. Once you get a CYA reading, you'll be able to go to testing and dosing with bleach in the evenings only. (By the way, take a look at the "Best Guess Chlorine Chart" in my signature line below.)

Another option is to use dichlor powder for a while which adds chlorine and CYA at the same time. If you do decide to use this, you'll have to keep an eye on your CYA level and when it gets to about 35-40, you'll need to stop using it and switch to another source of chlorine.

Also, you need to buy a good test kit. Click the link in my signature and you'll see the kit we recommend which is the Taylor K-2006 or 2006C. If you buy through that link, Pool Forum makes a little money.

Post a full set of readings for us to take a look at and we'll go from there. Do some reading on our sister site www.poolsolutions.com and you'll learn a lot.

I'll let someone else talk to you about your DE filter.

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