Bitter/metallic taste points to a specific filter issue or water chemistry.
DIAGNOSIS: The post-carbon filter is spent, or your feed water has unusual contaminants.
FIX:
- Replace the post-carbon (polishing) filter immediately. This filter's sole job is to remove any final tastes or odors after the membrane.
- Check if your pre-filters (sediment and carbon blocks) are also due for replacement. A saturated pre-filter can't protect the membrane.
IF THAT DIDN'T WORK:
- Test your feed water. High levels of specific inorganic salts (metals) can impart a metallic taste. The RO membrane should remove these, but a compromised membrane won't.
- Sanitize the system. Biofilm in the storage tank or lines can cause off-tastes. Follow the manufacturer's sanitization procedure.
HEADS UP: Water with TDS between 300-600 mg/liter is rated 'good' for taste. If your product water is in that range post-filter change, the taste should improve. If not, investigate the membrane.