Seemed impossible at the time
Bought a house 2 years ago that sat empty for 2 years. This was the condition of the pool just after I purchased the house. Started the pump and filter in March. Had crystal clear water in 3 weeks. I was sure I would have to empty the pool and start all over. Thankfully, the plumbing was all in tact. Just had to install a new pump motor and cartridge filter and I was in business. Took a sample of my water to the local hardware store and followed every instruction they gave me to the "T". Lesson learned - when it comes to pool chemistry do exactly what the experts tell you to do. Don't think that you know better than they do. It worked for me.
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https://lh5.googleusercontent.com/nC...w270-h205-p-no
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Aside from stains due to all the algae sitting on the bottom (I scooped out 35 gal with a leaf skimmer) the pool is in fairly good shape.