For three years I have been caring for my pool using the BBB method and you have no idea how much I appreciate the knowledge you have shared. I had never had any trouble but I am now stumped and hope you will share your insight. I do ask for your patience as I may not be as well-versed when it comes to equipment terms. Apologies in advance for the length of the post.
Our pool has a spa with a spillway, and while we swim regularly, the spa is seldom used (and I must admit is neglected at times with leaves sitting at the bottom for longer than should be). Yesterday our pool was its sparkly self when I noticed patches of algae on the walls of the spa. I proceeded to shock the spa as per Pool School protocol, but thought it best to turn off the filter pump to the pool and turn on the spa mode only- I figured it was easier to shock the contained spa water. The numbers were as follows:
20,000 gal. Pebble Tec (Houston area)
CC: 0 (pool)
Water Temp: 89 / Cloudy Weather
TFT FAS/DPD chlorine test
Taylor K2005 for everything else
Confession: I only tested the pool water; I did not test the spa. I just assumed that I needed to raise the chlorine to 12, so I proceeded to add bleach to the spa, however, when I tested the spa water after dosing, it showed a FC of 0, and CC a dark amber (I figured it would be useless to waste reagent to try to figure out what it was). I thought that the bleach was used up by the algae, so I added more. I kept testing, and adding more and more. The spa water became clear, but yellow, while still testing at 0 FC, and still amber CC. I then became concerned that I had added way more bleach than I should have for such a small volume of water (9ft round spa) so since the water was clear (albeit yellow), I returned to regular pool mode. I tested the pool water at this time and it gave me a reading of FC: 30 (!). While I was concerned at how the chlorine had gone up in the pool, I was relieved knowing that at least the level would be high enough to do away with any organics spilling from the spa. However, I tested again one hour later and the FC was 0 (!!), and CC amber. I just tested and indeed FC is 0, CC somewhat lighter yellow color. The spa now looks back to normal, the pool is clear; it is hard to gage the color since the sun has gone down, but it looks very slightly green.
Please give me your impressions on how you think I should proceed. Are the FC/CC readings off because of the ridiculous amount of bleach I added? Or do I trust that in fact my pool water has 0 chlorine and organic matter in it? Could the FC really have swung from 4 ppm to 30 ppm and then to 0 ppm? If I added bleach to the spa only, how did it get to the pool?
Thanks for your help.