I have an inground pool, approx 25000-30000 gallons, vinyl, sand filter. I don't have current measurements to report.
Last year the pool was opened, but then the filter broke, and I left the pool just sitting there, so it got very green and murky. Stupidly, I think the solar cover was on it for most of the year too. Filter was fixed, and then the pool was given a cursory shock and a couple vacuums and allowed to filter/pump a bit, and closed.
The pool store informed me that given the super super low (non existant) measurements of chlorine and algaecide, the pool would need a TON of chlorine, etc added. Like on the order of $300 of chlorine at least. OR, that water changes could be done, which we are now doing.
The plan is to do three water changes (maybe more, if it's advised) or it would be nice to only have to do two. Each time trying to change around 30% of the water. To avoid having to spend as much on chemicals.
From researching, I decided (of course) that the smartest thing to buy would be the 5.25% cheapest bleach. So after changing the water, what do I do? Add Borax and Baking Soda bits at a time to get the total alkalinity & pH good? And calcium chloride for calcium hardness. Assuming they are low, I figure they are very low. Does one have to come before the other? Then do I need to buy some other stabilizer so that the added chlorine doesn't go to waste, or does the Borax do that too/enough? Add some stabilizer, then add bleach, test, add more stabilizer, then more bleach on and on? (Meanwhile making sure the other 3 readings don't go funny.) What else? Easier ways/tricks given this situation?
I know at the end I can vacuum, add Super Flock Out and run the filter a bunch, and repeat. Thank you very much!