I replaced the sand yesterday, and added 1/2 gal 12.5% bleach and 18oz of CYA. Everything looks good, except CL drops to near zero during the day. The pre-sand check showed CYA below measurment level. I'm tempted to add a gallon of Leslie's fast-acting stabilizer, but I'm concerned I might overdo the CYA. Any comments on that? Now ready for some warm weather. Thanks for all the help.