I have been getting some very strange chlorine readings in my pool, and I have run out of ideas. So I'm turning it over to the sound advice of you all here. I will try to make a long story as short as possible.
I use a Taylor Test Kit.
MY FC I normally keep about 6, based on my CYA of 43.
I normally check my FC and PH about every other day, just because I know my pools habits. I usually add about a third of a gallon of bleach per day which replaces a consistent 3ppm FC loss due to sunlight.
So about three weeks ago I took the cover off for the first time this season. There was quite a bit of gunk in the water, but I ran the vaccume for a few hours, and everything looked great. All numbers were great. I put the cover back on, and left it on.
This Wednesday, I went to do my normal chlorine check and it was 0. Uh oh, something is eating it, so I began the shock process, bringing FC up to 18. Overnight, I had a 6 point loss! Bad! So, I took off the cover to see if something weird was under there, and sure enough, a big dead bloated gopher! I got him out. The water looked off. Not horrible, but a bit murky and not sparkly like it should. CC was 0.
I continued to shock, assuming the dead gopher was causing all this. That night, another 6 point loss, but the next day the water looked great. Sparkly, beautiful.
Here is where it gets weird: I figured the worst was over and things would stabilize. The weekend rolled around and I was able to test more frequently. Wanting to keep things at shock level, I did a test mid-day, and I was shocked to find a 6 point drop in only three hours! Then I noticed how much bleach I was going through; way more than I did last time I shocked. I had used 10 gallons in three days! So I test FC; it had again dropped from 18-13 in just a few hours. I poured in a whole gallon of bleach to really bump it up high. An hour later, I had only moved from 13-15 with a gallon of bleach! This strange massive chlorine loss/inability to raise it continued all weekend. Now I've been shocking for four days; and I've run out of titrating reagent, so everything might have been for nothing. I don't know if the pool held last night or not because I ran out of agent right in the middle of my morning test.
Then this morning I noticed a small leak on under the pool heater. I remembered that I thought we had been losing water much more rapidly than normal in the pool. The leak looks like it has been there for a few days at least.
I'm very stumped with this. The water looks fantastic, but this massive chlorine loss and inability to raise it is very strange. I thought after four days of shocking with the water looking this good, things would stabilize.
Could the leak have something to do with this weirdness?
Sorry for such a long post, but I wanted everyone to have as much info as possible.