I have a 13x54 calcite tank with a Fleck 5600 head on it. I've recently learned two things about my situation:
1) The pH of my raw water is 5.67, and my treated water is 6.68. I have copper plumbing and have been told that I really should try to get the pH up to 7 to avoid leaks and corrosion. The sink in the guest bath occasionally drips, and there is some blue/green staining in that sink bowl. No problems observed elsewhere.
2) The Fleck 5600 only provides 7 gpm of backwash flow, and I've read that a 13-inch calcite tank should have about 10 gpm of backwash. The existing arrangement, however, has been in service without flow problems for years.
So my questions are as follows:
a) To raise the pH to at least 7.0, is it as simple as vacuuming out the existing calcite and replacing it with an 80/20 mix of calcite/corosex? If I do that, will the mixture be consumed evenly, or will the corosex be consumed first, leaving me with nothing but calcite after few months?
b) If I add corosex, how do I keep the pH from becoming too high? We're not high-flow users, with typical draws of 2-4 gpm. Water also sits in the neutralizer all night and all day while we're out of the house.
c) Do I need to replace the Fleck 5600 valve with a Fleck 2510, which can provide the proper 10 gpm flow? Or can I get by with the 5600 even after adding corosex (would removing the dlfc button help?)? My well pump provides 12 gpm.
Thanks for any help or advice.