When to install salt chlorinator system and Alchem2

[leff1rj]

Hello. New to forum.

I am replacing pool water this year because the chemistry is beyond control. My pool is 20' x 40' with an 8' hopper, inground vinyl liner. Capacity is about 35000 gallon. Pool was installed 9 years ago with automatic chlorinator and cartridge filter system. No heater. Have auto clean system in floor - these are pop up devices that force a stream of water out across floor moving the dirt to the deep end and out the main drain.

Thinking about changing to salt chlorinator system with AlChem2 system for auto control of ph and something called ORP.

Can I change mid season after I have started pool with new water using the chlorinator system to the salt chlorinator system and AlChem2 without having to replace the water again?

Thanks