I recently purchased a house with a 28' above ground pool, appears to be betwen 10-15 years old. I was a little late to the game in opening the pool this season, so algae has taken control of my pool. The winter cover, which was brand new, tore in the middle and the pillow popped through pouring dirty, bird bathy, algae ridden water into the pool for about two months. Given my limited knowledge and the situation I am running into some filtration issues.
The pump, a Hayward EC50AC, likely 2-3 years old, runs at 18PSI after cleaning and adding 4.5LBS of DE... seems kinda high based on what I have read on the forums here and elsewhere. Nonetheless, within 2 hours the pressure reports 22-23 PSI and the return is nearly zero. I do have an inline clorinator, which was replaced last year... though I don't think that is a variable in this situation.
More background. So when I pulled the cover off, in pieces, what was left of the nasty water, naturally, poured into the pool. I added about 20% new water, level was about an inch below the return inlet. I then took the filter apart, hosed everything off, the perflex tubes appeared to be in good condition, not torn and for the most part white. Once I got the filter setup, I added 4 gallons of liquid shock to the pool to jump start things. Additionally I added some PH increaser, a constant battle last year and something called black algae preventer (the entire contents, about 2 quarts). I tested the water with some test strips I picked up from the local pool store about 12-hour post clorination + filter startup (2 hours ago). I found my PH to be on the higher end, 7.8ish, FC was 10ppm (max on the scale), and Total Aklalinity was about 120ppm, and Stabalizer (not sure about this one), was very low, between 0-30ppm. Within a few hours of running the filter output dropped to about nothing, I "regenerated" the filter and was able to run for another 45mins to an hour until repeating... each time less.
I am not sure what to do next. I could replace the DE and see if that helps, though I fear that the filter will just get clogged again. I need it to run at least 12 hours on a charge. I am considering an acid bath, but I have seen varying recommendations on the best method to clean up the filter. I don't know if my test strips provide enough information to provide to this community to help, so I am going to look for something better at the pool store. If I was to, what else should I be testing to determine the next steps? I haven't vacuumed the pool yet, I was only able to get 4-5 hours on the filter today. I don't want to waste the chemicals I already added... the pool is in the sun from about 5am to 8:30pm, mostly direct sunlight. Any thoughts with respect to next steps? Fortunately I took a three day weekend, so I am off tomorrow (Monday) to try and get this under control such that the filter will move water at least 12-hours a day.