New user with old vinyl pool

[markwg]

About the pool. 10 years old, 17 x 34 x 3.5 to 5' deep. Vinyl liner, gas heater, one return line. Liner is fading and has some wrinkles but does not leak. Installed a frogger system 2 years ago. Last year I had an issue with phosphates and repeated problems with algae. Algae again this year, brown stains I removed with chlorine shock.

We had a pool in the 1980's and all I ever looked at was chlorine, ph and added algaecide once a week. Never had any problems. Now I add metal free, phos free, check for hardness and alkalinity and shock weekly due to past problems experienced. Seems to be some new issue every year.

Water looks good now, but I heard about your forum and thought I would try it out.