Water Sources for Carnivorous Plants: Columbia River vs. Coastal Lakes

A grower (Ross) ran out of rainwater. Portland tap water is okay; Vancouver, WA tap water is not. Asks about Columbia River water, Ocean Park WA tap, Loomis Lake, Black Lake (Long Beach Peninsula).

Jeff Dallas: Columbia River has high mineral content (drainage for many rivers)—alien clams/mussels thrive there; would kill CPs quickly. Distilled water is safe. Long Beach Peninsula coastal lakes likely fine—many have sphagnum bogs and D. rotundifolia. Dark water (Black Lake) = tannins = acidic = perfect for CPs.

Surface water in coastal, peat-influenced systems is typically low-mineral. Municipal water varies by source (surface vs. well). Testing TDS (target <50 ppm) is the only certainty.