is it okay to use my express water ro5dx if my tap water has super high dissolved solids? like over 1000?

Yes, but with important caveats. The system is designed for this, but maintenance frequency changes.

DIAGNOSIS: Feed water TDS > 1000 mg/liter.

FIX:

• Confirm TDS with a meter. Water above 1200 mg/liter is generally unacceptable for taste.
• Increase pre-filter change frequency. Sediment and carbon blocks clog faster with high TDS water.
• Expect shorter RO membrane life. It works harder to reject more solids. Plan for replacement every 12-18 months, not 2-3 years.

IF THAT DIDN'T WORK: If flow drops drastically or taste declines quickly:

1. Check feed water pressure. It must be >40 psi. Low pressure reduces membrane efficiency.
2. Ensure drain line flow is unrestricted. A clog increases pressure on the membrane concentrate side.

HEADS UP: Consult local health authorities. Identify the specific constituents (e.g., nitrate, fluoride) causing the high TDS. The system removes them, but you need to know your baseline. No health-based guideline exists for TDS itself, only for specific components.