Blackduck Lake vs Medicine Lake
Water quality, depth, fish species, and recreation comparison.
Medicine Lake reads lower on nutrients and algae than Blackduck Lake. Both are in Beltrami County, Minnesota.
Both Blackduck Lake and Medicine Lake sit in Minnesota. A same-state comparison strips out the state-level water-quality regime as a variable: any differences in the readings here are about the lakes themselves, not the agencies sampling them. The readings are close: Blackduck Lake and Medicine Lake sit within a narrow band of each other on phosphorus, chlorophyll-a and clarity. The per-parameter table below shows where the small differences actually live.
With readings this close, the choice between the two lakes turns on non-water-quality factors: depth, fish species, public access, distance from home. The per-lake pages below cover all of those.
Blackduck Lake
Murky, only visible to about 6.2 ft.
Medicine Lake
Moderate clarity, visible to about 7.9 ft.
Side-by-Side Metrics
| Metric | Blackduck Lake | Medicine Lake |
|---|---|---|
| Water Clarity | 6.2 ft | 7.9 ft Better |
| Phosphorus | 34 µg/L | 23 µg/L Better |
| Chlorophyll-a (Algae) | 12.3 µg/L | 7.1 µg/L Better |
| Maximum Depth | 28 ft | 44 ft Better |
| Surface Area | 2,711 acres | 461 acres |
| Public Access | Yes | Yes |
| Fish Species | 16 Better | 12 |
| Trophic State | eutrophic | mesotrophic |
A green ✓ marks the better value for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better). Surface area and trophic state carry no tick — a bigger lake is not a better lake.
Swap a lake
Compare Blackduck Lake or Medicine Lake against a different lake.
Verdict
Medicine Lake reads lower on nutrients and algae than Blackduck Lake. Water clarity: 7.9 ft vs 6.2 ft. For more fish-species variety, Blackduck Lake edges ahead with 16 documented species.
Source: EPA National Aquatic Resource Surveys, 2026.