Sorry in advance for the wall of text but we've had a month long "journey" trying to get a new to us pool opened. I've read a good portion of topics in the pool school and will be ordering my Taylor kit shortly as it seems everything is based on the readings and resolution that it provides. I have included as much detail as possible in hopes that someone can find something we overlooked.
For a little background on the pool. Purchased a house in CT *that came with a 18' x 33' x 52" vinyl above ground pool and a 22inch sand filter. The previous owner had installed it 10 years ago and unfortunately a divorce caused him to be out of the house which meant that his son closed the pool. The filter was never disconnected and I don't know if any chemicals were added before the cover was put on. The pre-pot strainer housing, pressure gauge, and filter drain cap all broke due to freezing. The water level dropped to below the inlet sometime after these pieces had broke. The cover was basically fully intact and we were able to see the bottom partially when looking from the side.
On May 10th we removed as many leaves off the cover as feasible and pulled the cover. The remaining water and leaves dropped into the pool. The pool was filled with approximately 6-8" of well water to bring the level to the middle of the skimmer opening. Since the filter was still broken at this point, we continued to pull as much debris out as possible with a skimmer. By the end of the day, the pool was a murky green from stirring up the debris/water and went to almost dark lagoon green by the next morning.
For the next week we continued to pull out debris, add shock, and skim the surface. In total that week we added 6 gallons of shock and a floating chlorinator with one 3" tablet. It went from the dark green to a more reasonable algae green.*
That weekend (5/18) the filter was repaired and we began to run it for ~8-12 hours a day at ~15psi (2-speed - high setting). I didn't want it running while I was away for fear of any issues. At this point we began to gain approximately 0.5-1" of clarity at the top of the water but it generally stayed the same hue of green. Whenever the filter ran up to ~20psi, I backwashed and rinsed until the outlet was as clear as it could get.
Here's the first picture I took on 5/20.
On 5/24 we moved to a 20-24 hour a day pump cycle and added 2 bottles of algaecide 50, 1 bottle of clarifier and another 2 gallons of shock. We had a good amount of foam and we brushed the entire pool.
Picture from before chemicals
Picture after chemicals
The whole week the filter was run basically 24 hours a day with only a 15-30 gap of downtime due to the timer wheel setting. Every morning and evening the pool was skimmed to remove the foam as thoroughly as possible. We brushed every 2 or 3 days and continued to backwash as needed. At this point I had a good foamy/brown flow coming out when I backwashed and the color would be best described as green with a tan hue. The chlorine reading I was getting with my kit was still a constant highlighter yellow above the 3ppm scale. We had the water tested at this point by 2 different stores and they said all the levels were fine except for low calcium. Bought the calcium but never added it.
5/31 We changed the 150lbs of sand in the filter, checked the internal "spider" for damage, and removed the ladder from the pool. The internals were fine and the ladder had a brown film even though we had been brushing it also. After the ladder was left out in the sun the exposed side went back to white.
Here's a picture of the pool before the sand was changed.
6/2 The pool was vacuumed and the bottom was not too filmy or dirty. The bottom does have a good number of folds and creases by feel. There was some dirt/sand? build up under the outlet and skimmer basket. The vacuuming stirred up the water even more and it looked worse.
Here's the picture while it was being vacuumed.
6/5 We added 5 bags of powdered shock as there was a very heavy rainstorm coming and to this point there wasn't much progress even though we continued to brush and skim as often as we could. I lose visibility of the skimmer or brush at ~2ft below the surface.
6/9 Added another 4 gallons of shock after we had one day were the pool looked more green than the previous day. Checked the chlorine before adding it and it was still over 3ppm but was getting closer to the top of the scale in color. Also bleached the top rails.
6/12 Still have ~2ft visibility, chlorine levels highlighter yellow again and placed the vacuum tube in the bottom center of the pool to try and pull water through the filter from a different location. Overnight we had a good amount of foam build up as the skimmer wasn't able to pull anything off the surface with the vacuum connected.*
Here's the picture of the pool as of this morning*
The foam that has been forming throughout the process is white/brown and we continue to brush/skim/vacuum. pH has been ideal or slightly high (7.4-8.0).
The ultimatum has been placed recently and I have another week and a half of trying before the whole pool is drained and water delivered. I'd rather not go down that route because we'll still need to play the chemistry game as they bring water straight from a nearby town supply for an outrageous cost.*
Thanks for any help in advance,