Per this forum it is recommended to keep the CYA levels in a SWG pool somewhere between 70-90 and FC around 5. However, reading the owners manual for the Pentair IChlor 30, it states to maintain CYA between 30-50 and to not exceed FC above 4. Which is the correct levels to follow? Is there any harm in following TFP levels? The Pentair manual states that FC above 4 can cause damage to metals.