In other words, your chlorine level is 'way too low. That was obvious when I saw it was 4.0 (Total C, not FC) and CYA=90. 90 implies keeping your FC close to 10--the 5 to 10 range is for 60-90. You're at the top, keep your FC at the top.

That's the most obvious reason for your clouding...you don't have enough chlorine. To lower CYA, you have to drain off water. If you drain half your water your CYA will be half.

Don't chlorinate with Tri-chlor tablets or even di-chlor powder. Stick strictly to bleach and liquid chlorine or the problem will get worse.

Good Luck!