Developing a Large Florida Pond: Erosion, Shell, Plants, Fish

Project

100×30 ft excavated pit in SW Florida. Starting with waterfall for aeration. Questions: grass control on edges, crushed shell for water clarity, plants for fluctuating levels, heat-tolerant fish.

Edge Vegetation

Don't poison grass. Plant drought-tolerant marginals: spike rush, dwarf cattail, pickerelweed, blue flag iris. They stabilize banks, filter runoff, provide habitat.

Crushed Shell

Crushed oyster shell raises pH/hardness slightly. May help if water is acidic. Won't seal leaks. If bottom is "soft mush" (not clay), you need a liner (EPDM, bentonite, or sodium bentonite clay).

Plants for Fluctuating Levels

• Marginals (wet/dry): Canna, swamp hibiscus, cardinal flower.
• Submerged: Vallisneria, Sagittaria (adapt to depth changes).
• Floaters: Water lettuce, hyacinth (may die in winter).

Heat-Tolerant Fish

• Native: Bluegill, redear sunfish, flagfish, sailfin molly.
• Non-native (check legality): Tilapia (excellent algae control, die <55°F), cichlids.
• Avoid trout, salmon, goldfish (heat stress).

Resources

Farm pond guides: fishpondinfo.com/farm.htm. Plant lists: hardy plants index.