Sediment/Carbon prefilter or Carbon Post Filter is clogged. Replace Filters. Low incoming water pressure. Incoming water pressure must be above 40 PSI. The person intro me the water filter shown me the fact that Elken water s too clean until its water become asidic which is not needed by our body. Some more the price is so expensive. Some more the price is so expensive. Elken Bio Pure K Series PERFECT FUNCTIONALITY Perfectly Pure Water Bio Pure K-100 uses the 5-stage Reverse Osmosis (R.O.) Purification System -- the secret t.