
Water mint
Mentha aquatica

Mentha aquatica
Lives wild in Albania, Algeria, Angola, Austria, Baltic States, Belgium, Botswana, Bulgaria, and 43 more countries.
Introduced to Argentina, Bermuda, Bolivia, Brazil, Chile, Costa Rica, Iceland, Mexico, and 3 more countries.
Mentha aquatica (water mint; syn. Mentha hirsuta Huds.) is a perennial flowering plant in the mint family, Lamiaceae. It grows in moist places and is native to much of Europe, northwest Africa and southwest Asia.
Two completely different aquariums: forest rivers with soft, brown water, roots and leaves, and Rift Valley lake cichlids in hard, alkaline water with big rock piles.
Two aquariums from Southeast Asia: calm forest streams and peat swamps with soft, brown water, and fast mountain streams with cool, oxygen-rich water.
A coldwater aquarium with European fish and plants, without a heater. The water follows the seasons, and summer heat is the biggest problem.
Light, nutrients and CO₂ in balance, low tech versus high tech, and how to read from the leaves what your plants are missing.