Complex sentence: It was a uniquely safe design for children because there was no "deep end" anywhere around the periphery of the pool/pond; however, it lacked a formal filtration system and required attendants to periodically row out and manually add chlorine to the water.
Split into simpler sentences: It was a uniquely safe design for children because there was no "deep end" anywhere around the periphery of the pool/pond. Unfortunately, it lacked a formal filtration system and required attendants to periodically row out and manually add chlorine to the water.