Stabilizer is the CYA levels. It will affect how quickly your CL will be broken down by sunlight and general effectiveness of CL sanitization. Generally recommended to keep that at 40-50ppm level but because yours is REALLY high, you will have to keep your chlorine levels much higher to be effective.

If you have read the best guess chart, you will see that your chlorine levels must remain between 8 and 15 at all times to prevent algae and other nasties from growing.
CYA LVL
100 - 200

CL MIN
8ppm CL

CL MAX
15ppm CL

SHOCK LEVELS
25-100ppm CL

Caution: red levels (the high end of the shock levels) are can be irritating to skin, can
damage hair, lighten pool liners and are very damaging to swimwear. Additionally, at these stabilizer levels, chlorine will drop VERY slowly. This can make the pool unusable for a long period.