Over the summer my pump motor broke, which I replaced with a A.O. Smith ST1152. I have a C4000 Hayward filter system. I just received 4 new cartridges today (the cartridges in the unit are 10+ years old). I also have a Baracuda G3.

Because the pump motor broke I let the pool 'go.' I've been in the process of cleaning it up, but because my cartridges were so old & a leaking & broken pressure valve on the c4000 was messing up the overall filter pressure, it has been a lackluster process.

I've switched over to liquid bleach as my primary chlorination method. I've also ordered a Taylor K2006, it should be here on Thursday.

My question is this: Should I empty my pool & start over with my new cartridges? If I do that, what chemicals do I need to add to the 'new' water? Is the water I have salvageable? If it is, how would I find that out?

Pool Info:

Pool size = 20k gallons (I think)
Filter = Cartridge
Type = IG (plaster)

Thanks in advance!

-Scott