close but not quite?

[PoolCleanerMom]

I think I know the answer to this but before I drop another chlorine bomb, I wanted a second opinion
Had a mild dose of algae on the side of the pool on Wednesday. Brought FC upwards of 14 (it was 14 at 11 p.m. on 6/12), brushed often, left pump running overnight.
7 a.m. on 6/13 my FC was 13 so I thought I was done.
Didn't test again until this morning at 10 a.m. and FC is 7.0 ?! (CYA is about 50)/ I realize that the recommended shock level for CYA50 is 20ppm but since the water didn't *look* too bad I was hoping to get the algae out with a slightly lower ppm so we wouldn't have to wait as long to get back in the pool. Am I being ounce-wise and gallon-foolish with the chlorine here and should I just bite the bullet and bring the FC up to 20 for a day (or keep it at 7 for the weekend and then shock it if we want to use the pool this weekend)?

Thanks!


pool looks like this -

View from deep end



Close up of deep end



Close up of shallow end

 

[PoolCleanerMom]

anyone? I'm assuming that a 6ppm drop in FC over a 27-hour period is more than can be attributed to a sunny day's worth of UV's? (BTW what is a "normal" amount of sunny-day UV-related chlorine loss?)

 

[Richard320]

There's three tests to pass before you can say you're done.
Clear water
Lose 1 FC or less overnight
CC less than .5 I don't see that....

However, losing only 3 ppm per day with low CYA isn't too bad.

Understand that the pool is like a living thing - you have to feed it every day.

Also note you can swim up to shock level for your CYA.

 

[PoolCleanerMom]

Just did the CC test and no CC detected (my R-003 reagent is a bit old though so could that be a false negative?)
Water is clear although there's a slight haze of dust where I brush.

 

[nismostate]

if your not swimming today, i would bring it to shock and let it drift down for the weekend and keep it above 7 FC. Like Richard stated, you can swim up to shock level for your CYA

 

[PoolCleanerMom]

OK bringing FC up - at 15ppm now. So do I try to hold it at around 20 ppm until sundown? Almost seems like overkill when the water *looks* mostly blue and clear but after a few weeks of maybe-it's-gone-maybe-it's-not I'm wanting to get these buggers chlorinated out for sure. Have done a little extra scrubbing around where the vacuum hose connects and around the skimmer and the grout and any other suspected algal hideouts. Fingers crossed.....

Here's how it looks after another brushing:

Side view


Deep end

 

[msgtdan]

I'd just take a reading after the sun is off it and then see if it's within 1ppm before the sun is on it in the morning.

 

[PoolCleanerMom]

FC was 11.5 at 11 pm last night and still 11.5 at 7 am this morning

FC at 2:30 pm was 8ppm - is that within a "normal" range of FC loss for CYA50?
Water looks bluer than yesterday, slightly opaque after brushing

 

[UnderWaterVanya]

FC was 11.5 at 11 pm last night and still 11.5 at 7 am this morning

FC at 2:30 pm was 8ppm - is that within a "normal" range of FC loss for CYA50?
Water looks bluer than yesterday, slightly opaque after brushing

If not crystal clear keep shocking...

Sent via Tapatalk...

 

[Richard320]

FC was 11.5 at 11 pm last night and still 11.5 at 7 am this morning

FC at 2:30 pm was 8ppm - is that within a "normal" range of FC loss for CYA50?
Water looks bluer than yesterday, slightly opaque after brushing

It might be time to re-read that article on how to shock your pool.

Sound sto me like maybe all that's left is a good brushing to get all the fine gunk in suspension so the filter can grab it and maybe pool-school/add_de_to_a_sand_filter

Ask the neighbors who have a pool. If someone has a DE filter, they probably have a big bag of the stuff, and all you need is like an empty margarine tub's worth.