Tadpoles Bloating & Dying in New Cement Pond

New 700-800 gal cement pond (Surecoat sealed) stocked with goldfish, tadpoles, newt, crayfish, mosquito fish, insects, nymphs. Tadpoles bloat, float, die within days. Waterfall runs 15 hrs/day.

Key Issues

• Pump off at night: Oxygen crashes when photosynthesis stops. Run 24/7.
• New pond syndrome: Biofilter immature—ammonia/nitrite spikes likely.
• Overstocking tadpoles: 100+ tadpoles + fish + crayfish in 800 gal = high bioload, food competition.
• Crayfish & mosquito fish: Both prey on tadpoles.
• Bloating: Suggests bacterial/fungal infection or osmotic stress from water chemistry shock.

Corrective Steps

1. Run pump 24/7.
2. Test pH, ammonia, nitrite, nitrate, oxygen.
3. Add pond salt (1/2 dose for planted ponds).
4. Reduce tadpole numbers (rehome).
5. Remove crayfish if tadpole survival is priority.
6. Add beneficial bacteria starter.

Tadpoles thrive in mature, stable ponds. This system needs time to cycle.