The PoolRx blue minerals have dissolved rapidly from the cylinder?

This is by design. All the minerals completely release out of the unit and through the filter into the whole body of water within 4 – 6 hours of being placed in the skimmer (or pump basket). The minerals form a stable residual throughout the whole body of water eliminating the algae and bacteria wherever they may be in the pool. These minerals recharge ionically as they pass again through the PoolRx cylinder.