CrystalClear pHGuard will stabilize pond water pH and maintain buffering capacity as safe levels between 80-240 ppm. pHGuard will help prevent wide pH swings which are typical from morning to night. CrystalClear pHGuard makes pond water safe for fish and plants and helps keep water balanced in the hot summer months. Keeping a properly buffered system is essential for the completion of the nitrification process which allows harmful ammonia to be converted to nitrite and then to nitrate.