First of all thanks for all the helpful info on this site. Learned a lot from the Pool School and by reviewing the experiences of others.
Been operating my 14x30 foot in-ground backyard pool (12K gal) since 1993 and once in operation with chemistry balanced, it is very stable over the summer months. However startup in recent years has become more and more challenging often with no FC readings initially after adding 3lbs of chlorine shock followed many gallons of 12.5% pool bleach, high CC readings too, low to very low CYA levels, low PH levels needing PH+ and in some years low Total Alkalinity as well. My pool's chemistry really deteriorates over the winter. For 15yrs startup was easy and simple. Add a few lbs of chlorine and non-chlorine shock and some PH+ and all was fine. Now it takes a week or longer to get it all in balance. I wonder what's changed?
I keep thinking that my "winterizing" could be the source of the problem. Yet I vacuum and brush all surfaces well before closing, use a qt. of winter algaecide, use a floater with several lbs. of non-chlorine bleach, use a bottle of Metal Free to sequester high iron levels in our city water, and cover with a heavy-weight vinyl winter cover with a black side on the water side to retard algae growth over the winter. Nitrogen runoff into pool over winter is unlikely. Only small plots of fertilized grass are near my pool.
Yet each spring in recent years it takes 7-10 gallons (sometimes more) of 12.5% bleach along with several more lbs. of chlorine and non-chlorine shock to get any FC readings on test strips. Using TF-100 this year I discovered that my CC readings were rising along with FC readings as bleach was added -- almost 1 for 1. We had a very rough winter here in Michigan and yet even though I opened up the pool earlier than usual with the water still cold, the pool water was green with algae. The pool cleared in about 5-days running pump 24/7. Pool store experts at two stores said I had high FC readings yet no test strip showed any FC. In desperation I just added several more gal. of pool bleach and suddenly my strip readings showed FC and CC took a nosedive. What is happening over the winter months and any way to prevent these problems?
With the summer just underway, I know it is strange to be asking about winterizing. Yet I'm fed up with "startup" hassle of recent years and would like to prevent it if I can. Does anyone have any special winterizing products or techniques to insure less chloramine formation and fewer start-up problems in the spring? It is very difficult for me to add chemicals to the pool over the winter months. Any special procedures beyond what I am doing to insure an easier pool opening as in years past? Appreciate any advice or suggestions.