The Orenda Startup is all about filling a newly-surfaced pool with slightly-positive LSI-balanced water (+0.20 to +0.30). The process depends on the chemistry of the fill water, and how you fill the pool. Normally the Orenda Startup entails adding pre-dissolved and chelated calcium (or in rare cases, sodium bicarb) as the pool is filling. Positive-LSI water prevents the loss of calcium hydroxide from cement, which in turn can prevent plaster dust and pH spiking.