I moved into my new house with 20+year old pool in June and have been doing the TFP method ever since. The pool water finally became crystal clear a couple of weeks ago.
However, I have been noticing what appears to be dirt OR mustard algae on some of the walls (near the bottom, never near the top) and the floor of the pool. oh, it ALWAYS seems to be prevalent over this one large mosaic on the pool floor. I usually brush the brownish looking dirt and it comes off in a small cloud.
Is it possible this is dirt from some construction I am having done on the house? They have been tearing out drywall, knocking out fixtures, and creating a lot of dust, AND they are adjacent to my pool (and that mosaic too). OR, do you think it is the beginning of mustard algae? I did an OCLT after I first noticed the paint and some of the dirt, and i lost no more than .5 FC. My CC is constantly zero. I HAVE allowed FC to drop to as low as 2.5 a couple of times but have added chlorine immediately to bring up my FC to 6 or 7 (CYA is 40), which I normally maintain.
I also have a "solar" cover and have been maintaining temps around 88 degrees (I always thought warmer water was ideal for algae growth).
Knowing all of this, do you think I have mustard algae? I have NEVER SLAMmed my pool yet, so maybe I should? OR... should I wait until the construction is complete and see if this dirt / algae stops appearing? Since my filter seems undersized for the pool, I have had to rinse it out every 1 or 2 weeks. Each time, that brown stuff is definitely caught and evident on the cartridges. If it was mustard algae would I be seeing it on the filter cartridges?
I don't like seeing the brown patches every few days and I know a proper slam and MA slam would eliminate it IF it were algae, but wanted your two cents about this matter.
I just read the topic on SLAMming. maybe I don't need to SLAM, but just bring my FC to MA levels for 24 hours and during that time, brush EVERYTHING, including the light niche?
Thanks in advance!