Crystal clear pool but maybe algae problem

[damato300x7]

So I have been following the TFP method for over a week and my pool has never been so sparkling clear. One problem if I sweep the pool today by tomorrow evening there will be like a white sediment that settles into the small crevices on the bottom of the pool. I have done the OCLT a couple times now and my chlorine drops 2ppm over night. Here are my most recent numbers taken this morning at 630:

FC - 3.5
CC - .5
PH - 7.6
TA - 130
CYA - 45
Temp - 78

I added 1/2 gallon of 8.25% bleach just to get it up to acceptable level. I did not have time to retest before I left for work. When I returned home my FC had dropped to 1.5ppm. So I added a gallon of 8.25% bleach and that raised my level to 8ppm. I will check in the morning to see how much it drops.

I think I need to get the pool to shock level but I am having a hard time convincing my wife that the pool needs shocked when it is so crystal clear. We have had this pool for 11 years and we have never seen it this clear since we started following the TFP method.

Do I need to increase to shock level and sustain it there until I pass the OCLT?

Thanks

 

[AimeeH]

Hi

With an overnight chlorine loss like you say.......I'd SLAM

Just to clarify, you are losing that much chlorine after dark and before sunrise?

 

[damato300x7]

Yes, I took the test right after the sun was no longer hitting my pool and took it in the morning before the sun started hitting my pool.

 

[woodyp]

Your SLAM level of FC for your CYA is 18. 8 FC ain't gonna get you there.

 

[damato300x7]

Yes I know this. trying to convince my wife that I need to raise the chlorine that high and her not being able to use the pool for the next week is a realllll hard sell when she goes out there and it is crystal clear.

 

[pooldv]

I SLAMed last summer with CYA at 70 and FC at 28 for 2 weeks. We swam every day and nobody even noticed.

 

[AimeeH]

Are her swimsuits the really expensive type?......like $100 dollar tops for extra support?

If not. Don't tell her. .......that's my recommendation. It's safe to swim at choline levels at shock for your CYA.

 

[damato300x7]

Well that is good to know. I didn't realize it would be safe to swim with a FC level that high. Im going to have a tough time keeping it elevated during the week when I am at work. I can add in the morning and in the evening. And check more on the weekends. Will this work?

 

[pooldv]

Yes, it will work. More is always better and works faster but all you can do is all you can do.

 

[damato300x7]

She already calls me a mad scientist when I am testing the water! hahaha. Before this year we would just have test strips. But now I have a test kit, she gets a kick out of it. But she also loves how clean and clear the pool is.

 

[woodyp]

Don't tell her you're adding any and just ask her to help maintain FC loss during the day and kick in a few FC a half hour before she jumps in!

 

[damato300x7]

Ok just went and added the recommended amount to raise my level to 18. Will see what it reads in the morning.

Thanks

 

[AimeeH]

Yep..... I'm the she and not the he in our pool care relationship. Hubby doesn't have a clue about the pool.......doesn't know how to vacuum it....nothing. I'll give him credit for performing the fas-dpd chlorine test since he works from home but he had to call me at work to clarify what to do.

Chlorine at slam level "might" degrade swimsuits a bit. But I've never had a problem. And I buy the expensive ones.

 

[MarianParoo]

If you are trying an OCLT, please test about an hour after that addition to know your exact result. It may not be exactly 18.

In the future, I would recommend always waiting until after sunset, (not just after no sun is hitting the pool), and in the morning within a half hour of sunrise, (again, not just before direct sun hits the pool). FC gets consumed by UV rays even on a cloudy day.

 

[damato300x7]

Not trying an OCLT, I have failed that many times now. Starting to SLAM because I am losing about 2ppm overnight. Pool is crystal clear just can't pass OCLT.

 

[MarianParoo]

Okay. Just keep that info in mind when you do. Good luck!

 

[damato300x7]

Thank you MarianParoo. I will check at about 845 at night which it is actually starting to get dark at that time and I get up at 6 am for work which it is still kinda dark out at that time.

Thanks

 

[MarianParoo]

If you assume you reach your target, and don't hit it, or over overshoot it, it will skew your OCLT results.

Here's a scenario if you don't retest your addition for the OCLT:

If your addition SHOULD bring you to 18, but only really only hit 17.5, you may think you didn't pass at 16.5.

Conversely, if that same addition actually brought you to 18.5, (and you thought it would be 18), you would think you were golden if the morning test was 17, when in fact that would be a loss of 1.5.

I hope that makes sense.