So I have metals in my pool and am currently doing a weekly maintenance dose of Jack Magic Vinyl Blue. I did a citric acid treatment approx 1 month ago and my daily chlorine usage has returned to normal (2 ppm/day). Here are my numbers:
I started adding DE to my sand filter a few weeks ago. Here's my issue. After a backwash, my sand filter runs at 16 PSI. I determined that 1 lb of DE will raise the filter 1 PSI (considerably more than the 4 cups or so recommended on the TFP). So my filter will then run at 17 PSI for a while, usually several days. Then, the pressure will suddenly spike 1 - 3 PSI very quickly. Today, after vacuuming and backwashing, I added the DE but dropped it down to 1/2 lb and added the maintenance dose of sequestrant. The PSI only raised up to 16.25 or so, not quite 16.5. It stayed there for a few hours, then suddenly jumped up to 20. The water is crystal clear.
So if I am filtering out metals I can stay the course. However, I feel like I may just be wasting water and DE. Any suggestions? I can't be backwashing twice in one day.