algae problem for months

[my_youngminds]

Well, I thought I might have gotten all of the algae, but from my readings today maybe not? Can someone tell me what they think and what my next step should be?

9am reading:
FC: 18.5
CC: 0
pH: 8.0

Did a backwash and ran the Rover pool vac continuously throughout the day.

3pm did another backwash.

6pm reading:
FC: 7.5! (Isn't that quite a drop? Especially since the weather is cloudy and rainy?)
CC: 0 (which kind of had me confused. Doesn't CC mean something is growing?)
pH: 7.4
Added 2 (182 oz. jugs) of 6% bleach, per the pool calculator's calculations to raise FC back up to 15.

8pm
FC: 16.5
CC: .5
pH: 8.2

Guess I'll see how much it drops overnight, correct? As that will tell me if I'm losing chlorine to something growing or the UV from the sun? Is that correct thinking? The water is a very "pretty" (as opposed to primordial soup green) milky, bluish color. I cannot see the bottom yet. At some point should I stop the filter to let the suspended stuff settle so it can be vacuumed to waste? Sorry for all of the posts. I feel like I am so close, but if I don't keep on top of it or do what needs to be done next, then I will lose control of it again. And I really don't want all of my $$ and time going to waste again. Thank you for any replies.

[Watermom]

You are thinking correctly in regards to the chlorine loss. The reason you are losing so much chlorine during the day is because of your CYA reading of 0. So, that can't tell us if you are still fighting something in the water. Only a chlorine loss overnight can give us that information.

It takes awhile to filter out dead algae especially when you have a larger than needed pump on an AG pool. In the case of pool pumps, bigger is NOT better. A too powerful pump forces debris through the sand bed instead of filtering it out very well.

[BigDave]

Filtration is what's going to remove the cloudy. Is your filter pressure rising?

With 0 CYA, you are going to lose alot of chlorine to sunlight - cloudy or not.

[my_youngminds]

Well, I think I have the algae beaten. It only dropped 1ppm for 2 nights. However, now we have Hurricane Sandy and I had to turn the pump off during this storm. I foresee it being off for at least 3 days. Last I checked (yesterday morning) the FC was at 17 and pH was at 7.7. Any suggestions on what I should expect or will probably need to do after the rain? Also, while it's raining I was reading up on increasing CYA and getting what I needed to do that and was a little overwhelmed with what I was reading here. Do I need to wait for my pool to be clear or just the algae beaten (but water still cloudy) to increase the CYA? Also, the small jar at the pool store was $$$$. It was $20 for 5 lbs! Is there a source/brand that you recommend? Thank you for your advice. It's been a tremendous help!

[PoolDoc]

membership updated.

Maintaining adequate chlorine (> 2.0 ppm where CYA = 0) should prevent the algae from regrowing. You can do this with 6% plain household bleach. Note that chlorine levels will drop RAPIDLY, once post-storm clear skies arrive, so add daily bleach doses late in the evening to allow them to work all night before being destroyed by sunlight.

[my_youngminds]

well, not sure what to do. We are currently without power and isn't anticipated to be back on until Monday. I checked the chlorine level this morning and the FC was 1, CC was .4 and pH was 7.3. Is it ok to walk along the edge of the pool and dump some bleach in, if it's not being circulated? On a positive not, the dead algae settled and I can see the bottom and the water is clear. So when we get power back I can give it a good vacuum to waste. Just trying to figure out what to do until we can get our pump running again. Thank you again for the suggestions.

[Charlie_R]

If you haven't already figured it out, yes, you can pour bleach in around the edges, and stir the water with your brush/broom.

[BigDave]

Watermom and I were posting at the same time - Sorry mom. Same advice though.

[waterbear]

9am reading:
FC: 18.5
CC: 0
pH: 8.0

Did a backwash and ran the Rover pool vac continuously throughout the day.

3pm did another backwash.

6pm reading:
FC: 7.5! (Isn't that quite a drop? Especially since the weather is cloudy and rainy?)
CC: 0 (which kind of had me confused. Doesn't CC mean something is growing?)
pH: 7.4
Added 2 (182 oz. jugs) of 6% bleach, per the pool calculator's calculations to raise FC back up to 15.

8pm
FC: 16.5
CC: .5
pH: 8.2

This is a GREAT illustration of how high FC levels can cause a false high pH reading! There is a chemical reason for this but the chemistry is somewhat complex so I will spare you the details. Just be aware that pH readings are suspect when the FC is above 10 ppm (but still 'usable, if not totally accurate up to about 15 ppm since the error is not that great).