New Pool - Something Wrong Already?

[speck]

New pool here! It was filled for the first time on May 30th. The pool builder maintained it for the first 1.5 months, and I've been taking a stab at it for the past 20 days or so. I ordered the TF-100 and paid for the Pool Math app.
So far, I've been adding enough bleach to get me to a FC of 6, but I'm still trying to figure out how often to add more. When I test every 4 days, FC is at 1 or 0.5. Not good - I know.
Rained several inches on 8/7, so I drained some out on 8/8. FC was 0, so I added bleach to get up to FC 6 and tested 1 hour later. The result was FC of 6.
Rained about an inch the night of 8/10, so on 8/11 I tested, and the FC was now at 0.5. I added bleach at 7:30pm for the FC of 6 again, and decided to do the OCLT.
At 11:30am the next morning, (forgot to do it earlier but it was cloudy all morning) FC was 3.0 and CC was 0.5. Tested again at 6pm - FC was 1.5 and CC was 1.0.

Other info - I brushed and vacuumed about 2 weeks ago. The cartridge filter was cleaned about a month ago. Pump is on 4 hours/day, which is enough to theoretically filter the water twice.

Pool still looks beautiful! Water is very clear. Any idea what's going on?

 

[Brett S]

When I test every 4 days, FC is at 1 or 0.5. Not good - I know.

This is a big part of the problem. Until you get used to how your pool behaves and how much chlorine you need to add you *need* to test every day. And you need to add chlorine every day no matter what. After a couple of weeks when you get used to how much chlorine your pool uses you’ll be able to cut back your testing to every few days, but right now you need to be testing every day.

 

[Newdude]

Hey Speck and belated Welcome !! 2-4ppm per day loss is expected. With every other day testing you should be expecting a loss of 8ppm in that span to not get caught behind the 8 ball. And that’s 8ppm using the high end of the target range. 8 ppm from the low end or minimum is trouble waiting to happen. What is your CYA ? You may need to increase it to help protect the FC due to the highest demand part of the sunny season in FL.

 

[PoolNewb2020]

I would perform another OCLT and measure FC early in the morning. 11am, cloudy or not, still exposes water to UV.
After that, post a full set of test results so that the experts can guide you from there.

 

[speck]

This is a big part of the problem. Until you get used to how your pool behaves and how much chlorine you need to add you *need* to test every day. And you need to add chlorine every day no matter what. After a couple of weeks when you get used to how much chlorine your pool uses you’ll be able to cut back your testing to every few days, but right now you need to be testing every day.

Noted! I will start testing every day. Will I always need to add chlorine every day?

Hey Speck and belated Welcome !! 2-4ppm per day loss is expected. With every other day testing you should be expecting a loss of 8ppm in that span to not get caught behind the 8 ball. And that’s 8ppm using the high end of the target range. 8 ppm from the low end or minimum is trouble waiting to happen. What is your CYA ? You may need to increase it to help protect the FC due to the highest demand part of the sunny season in FL.

I read a few posts on here about how increasing CYA to around 50 decreases FC loss, so I increased CYA from 35 to 45. It may be lower than that now due to the rain

 

[Newdude]

I read a few posts on here about how increasing CYA to around 50 decreases FC loss, so I increased CYA from 35 to 45. It may be lower than that now due to the rain

CYA always rounds up to the next '10'. Call you 45, 50 and road test it to see how it does.

Noted! I will start testing every day. Will I always need to add chlorine every day?

Daily top offs is easiest until you learn your pools appetite. Besides, its half a dozen or 6 anyway, add half twice or double once. Keep it topped off for now.

 

[Divin Dave]

Also to add to the others comments, seeing as you are in Tampa and subject to very high UV, you should be keeping your CYA on the higher side of TFP recommendations, maybe even increase it by 10 might help to reduce the CL consumption a little bit

 

[speck]

Also to add to the others comments, seeing as you are in Tampa and subject to very high UV, you should be keeping your CYA on the higher side of TFP recommendations, maybe even increase it by 10 might help to reduce the CL consumption a little bit

I read a few posts that talked about increasing CYA to 50. Is this what I should follow?

 

[JJ_Tex]

I read a few posts that talked about increasing CYA to 50. Is this what I should follow?

Yes if you get a lot of sun, but before you raise your CYA you need to make sure there isnt algae starting to form in your pool. I would start off with a proper OCLT and go from there.

 

[speck]

Yes if you get a lot of sun, but before you raise your CYA you need to make sure there isnt algae starting to form in your pool. I would start off with a proper OCLT and go from there.

Got it! I will do the OCLT tonight

 

[speck]

OCLT results:

Measured at 8pm - FC 6.0 CC 0.5
Measured at 6am - FC 6.0 CC 0.5

Not sure what was going on earlier this week, but it seems that everything is ok now!

Aside from daily testing and daily chlorine additions, is there anything else that I should be doing right now?

 

[mknauss]

is there anything else that I should be doing right now?

 

[Newdude]

Aside from daily testing and daily chlorine additions, is there anything else that I should be doing right now

A tasty beverage or 12 is nice.