Description
The Filtration Fern Pools consist of a series of interconnected shallow basins arranged in descending tiers near the Living Well, each pool measuring roughly ten feet across and two feet deep at its deepest point. The pools are formed from the same living root construction as the well itself, with ancient oaks and willows encouraged to grow their roots in carefully woven patterns that create watertight basins lined with smooth wood and sealed with natural resins. Water flows from one pool to the next through gentle cascades, each drop of only six to eight inches, creating a musical sound as the water tumbles over moss-covered edges. The entire system spans approximately fifty feet from the intake at the highest pool to the final output basin, creating a terraced water garden that serves both practical and aesthetic purposes. The dimensional bubble's accelerated growth properties allow the filtration plants to establish themselves in mere days rather than weeks, and to reproduce and spread at remarkable rates, ensuring the system remains densely planted and highly effective.
Each pool in the series contains different species of plants selected specifically for their water-purifying properties. The uppermost pool, which receives water pumped from the Crystal Streams or collected from rain runoff, hosts dense stands of cattails and bulrushes whose roots excel at trapping sediment and absorbing heavy metals. Their tall, sword-like leaves create a vertical green screen around this pool, and their roots form a thick, fibrous mat through which the water must pass before continuing downstream. The second pool features water hyacinths and water lettuce, floating plants whose trailing root systems dangle through the water column like living filters, their roots covered in beneficial bacteria that break down organic pollutants. These plants grow so rapidly in the dimensional bubble that they must be harvested every few days to prevent them from completely covering the water surface, though this abundance proves useful as the harvested plants become excellent compost material for the settlement's gardens.
The middle pools contain specialized ferns that give the system its name. Silverfern, native to the Elderwood Grove and magically enhanced by Goodberry, grows in extraordinary profusion along the pool edges and on floating reed mats anchored within the water. These ferns possess remarkable abilities to absorb impurities, their fronds turning slightly darker when filtering heavily contaminated water and returning to their characteristic silver-green when the water is pure. Water cress and mint grow alongside the ferns, their roots creating additional filtration layers while their leaves can be harvested for culinary use, making these pools both functional and productive. Beneath the water surface, submerged mosses coat the pool bottoms in thick carpets, their fine filaments capturing microscopic particles and providing surface area for beneficial bacteria colonies that break down harmful compounds into harmless ones.
The lower pools feature slower-growing but equally important plants. Water irises in purple and yellow create stunning visual displays while their robust root systems provide final-stage filtration. Papyrus and horsetail reeds grow in the shallowest areas, their presence indicating that the water quality has improved enough to support these more delicate species. The final pool, which serves as the collection basin for the filtered water, remains relatively plant-free except for a ring of flowering water lilies whose pristine blooms serve as living indicators of water purity. The lilies will only flower when water quality is exceptional, and their failure to bloom alerts the Pool Keepers to potential problems in the filtration system. From this final pool, clean water can be drawn directly for drinking, cooking, or other needs requiring the highest water quality. A small channel also allows excess water to flow back to the Crystal Streams, ensuring the system never overflows while returning the purified water to the natural watershed.
The Filtration Fern Pools quickly become one of the most beautiful features of the Elderwood Grove, attracting dragonflies, butterflies, and songbirds that appreciate the combination of clean water, abundant plant life, and insect populations. Residents often linger near the pools to enjoy their beauty and tranquility, watching the water cascade from level to level while breathing the fresh, slightly humid air that rises from the aquatic gardens. The gentle splashing sounds create a peaceful atmosphere, and many citizens report that spending time near the pools has a calming effect. Children are taught about the importance of water quality by observing how the plants work, seeing firsthand how cloudy water entering the top pools emerges crystal clear at the bottom. The system proves particularly valuable during times when the streams run muddy after heavy rains, as it can process this turbid water and produce drinking-quality output within hours of passing through the complete filtration series. The Pool Keepers maintain detailed records of water quality, plant health, and system performance, developing expertise in natural filtration that becomes valuable knowledge for the entire settlement.
Benefits
The Filtration Fern Pools purifies water every day, converting water from streams, rain runoff, or other sources into drinking-quality water that matches the purity of the Living Well. This purchase extends the number of people that effectively have water by 300. This upgrade is purchaseable multiple times, with no limit. This upgrade generates 2 Prestige each purchase, representing the settlement's advanced understanding of natural systems and commitment to environmental health.