Chlorine Lock ?

Brown / yellow dust that turned green when you swept it?

I would say more greenish brownish-clumpy. It has been over a week since being swept and with the filter pretty much going all the daylight hours, today was the first day that I looked at it very still. There was a lot of junk on the bottom. Pool has not had much use to stir it up. Could I still have algae or even dead algae settled on bottom?

Just went out and looked at pool again. Looks great-clear and sparkly. Could some of that staining disappeared this quickly??? Within the past 2 hours???

Yes, if the stains were organic, high chlorine can take care of them. Even though your water looks clear, still keep high chlorine until you meet the 3 criteria posted above.

Noticing some changes in pool this morning and have submitted pool history entries. Would it be possible for Watermom or PoolDoc to take a look?

Thanks for all your guidance and support!

Ok, you're reporting what sounds like mustard algae -- so you'll need even higher levels of chlorine.

BUT . . . I'm puzzled by the difference in readings between what you entered in the form, and what you entered in the notes. For example you entered pH=7.0 in the form, but in the notes you have pH=7.6 .

I am unable to enter decimal points on the form for some reason. I asked the tech guru in my household and he says that the keyboard that pops up on my tablet from your history form will not let me add symbols. I believe I have been entering the correct numbers with decimal points in the narrative section on pool history form.

Argh. I am SO not loving the transition from computers to tablets and phones! In so many ways, it's a technological step backwards, with smaller screens, worse keyboards, 'helper' apps that have unpredictable effects on data (and form!) entry, and so on.

I'm actually going to have drag out old pages from PoolSolutions, because they were better optimized for the smaller screen sizes typical of phones and tablets.

Personally, I have a 1920 x 1080 screen on both my desktop and my iPad . . . but naturally, the iPad is less than 1/4 as usable as the desktop. Of course, it IS easier to carry around.

Ok. Done whining for now.

I'm sure it is a challenge to keep up with tech advances which constantly set you back with changes. I am technologically challenged myself and depend on my 21 year old brainiac son to keep me on track! Back to my water... how much higher FC? I am trying to get it to that 25ppm and hold. Not there yet. Seems to go back to 21-22 FC over night and then again at dusk. Keep adding appropriate dose of bleach to get it to 25. Should that eventually take care of the mustard algae if I am diligent in vaccing to waste and brushing? I'm sorry I am so full of questions everyday...

No problem with the questions.

Chlorine => 25% of your CYA => ~35 ppm or HIGHER!

The other option is to use phosphate remover. Mustard algae is VERY chlorine resistant. I'd recommend first trying 35 ppm + daily brushing, and see if you can eradicate it that way. It's much easier to remove mustard algae from vinyl pools than other types. Do NOT use any of the mustard algae products -- they ALL have horrendous side effects. Don't bother with polyquat; it's not very effective against mustard algae.

If you want, you can try borates. Raising your borate level to 60 ppm improves the aesthetics of the pool water somewhat, and helps with green algae. It may help with mustard algae somewhat, AND it will help with winter maintenance. If you want to pursue that, you'll need 22 boxes of 20 Mule Team borax and about 6 gallons of PLAIN 31% muriatic acid, like the Crown Muriatic at Lowes

The remaining option is using a phosphate remover, but doing so successfully requires a definite plan and consistent efforts on your part. Simply adding phosphate remover without a plan and without accurate phosphate testing is likely to be nothing but a waste of money.