We have a 24' AG pool that was installed one year ago. I am new to owning pools, but have a strong background in science - which makes it all the more frustrating that I cannot seem to get our pool levels to stay consistently where they are supposed to be.
Last summer I had a terrible time keeping the chlorine levels above 1. We had an in-line chlorinator running on maximum, I added 4 cups of 12.5% liquid bleach per week, algeacide, stain-guard - everything the pool store said to do. We had two algal blooms resulting in lost swimming time and grey hair.
We opened the pool 3 weeks ago to cloudy water with leaves on the bottom. I added 5 gal 12.5% liquid chlorine, metal magic (since we had an iron issue last summer and we needed to add water), 2 gal liquid shock, 1 packet powdered shock, and algeacide over a couple weeks time and the water is now clear. Pool sits partially under a large black maple tree and gets quite a bit of debris which we remove daily.
I took a water sample to the local pool place 2 weeks ago and they said my phosphates were really high - well over 1000. I bought my own test and verified that. She recommended PhosFree. I did extensive reading on phosphates in pools on your forums and elsewhere which has left me frustrated and confused. I tried the PhosFree - adding a total of one 3L bottle over a few days time - and the levels did not seem to drop at all. We had to add water from all of the backwashing and vacuuming and our well water (we are in the middle of farmland and have farmers spraying all of the time) tests at 500ppb phosphates right out of the tap. I am wondering if the metal magic added the rest?
Here is the problem as I see it - it seems to me if I continue to add PhosFree and backwash and add more water, I am never going to get ahead of it. I realize that many people think phosphate levels are irrelevant - to a point. I am not sure exactly how high mine are - just know they are over 1000ppb. My CYA levels started at 0. I have added 2 pounds stabilizer to the skimmer which, after a week, raised it to 10. I put another pound of stabilizer in a sock and it is dissolving now.
QUESTION - Is it possible that super high phosphate levels are making it more difficult for me to keep my FC where it needs to be - or should I completely ignore it? If I ignore phosphate, how much chlorine should I have to be adding and how often in addition to the five 3 inch pucks I have floating in a dispenser? Why do I continue to have such low FC levels? (I did the SLAM method and got my CCs <0.5ppm and yes, I do have a kit I use to figure out my own FC/CC numbers). Am I destined to have to add extra Cl if I don't lower my PO4??
pH = 7.3
FC 1.5 (have been adding a couple of cups CL every night)
CYA about 10 last time tested at pool store
PO4 >1000 in pool, well water from tap = 500ppb
Pool is currently clear
Thank you for your help!!!!!!!!!!!!