i am using tap water, letting the ph ajust and also im watchin with a ph meter ,What kind of water are you using? Tap? Distilled? Like the guy above me said, could be PH. If you're using distilled then PH shouldn't be an issue. Overwatering can cause the leaves to yellow and/or die.
Why didn't you plant them in nuted soil? Being that you're new to growing, trying to feed the plant properly is going to be very difficult since you don't have anything to go by.
Also, cutting of the dead/yellow leaves isn't going to help anything. It might make the plant look better for a little while, but the problem is still going to be there and just spread to the healthy leaves.
My suggestion is to get some nuted soil and transplant. Use only distilled water and let the plants almost completely dry out before you water again. As far as what soil to use, you're going to get different opinions from everybody. I use Sta-Green Vegetable Mix. It's a bedding soil but the nutes aren't super strong. I add one bag of Miracle Gro perlite per cubic foot of soil. You could also get the Sta-Green Potting Mix, but I've never tried it. The Vegetable mix has never let me down.
If and when the plants recover. Wait until you see some yellowing at the bottom and give them 1/4 to 1/2 strength nutes. I use Miracle Gro All Purpose for veg and Miracle Gro Bloom Booster for flower. Again, everyone has different opinions on nutes, but that's what I use and it gets the job done.
I've found that a slightly neglected plant is always better than one that's over cared for. Problems resulting from over caring are usually harder to fix than ones that are brought on by the opposite.
Good luck.