Hi I'm having a plethora of problems with chlorine. We opened our pool about a month ago and we continue to have an absence of chlorine even when we have put a total of over 15 bags of shock into our 40,000 gallon pool. The water is still cloudy (blue) and nothing seems to be working. We have used test strips and also brought it into a professional tester. here are the results:

Chlorine:0
TCI:3
ALK:80
PH:7.2
Total Hardness:100

Our pool is vinyl with a pump that is sand and 2.7 sq. ft. And our pump pressure is only 10, it usually is 18ish (is that a problem?) How can i resolve this problem?