Cloudy water and shock level

[Red]

I've already read several posts about cloudy water. Using TFP articles and the pool calculator, I've concluded I need to raise FC to 12 and do the overnight FC test for 2 nights. Last night I had no measurable FC loss. I'm trying it again tonight. I've been running the filter on high for a day and a half now and brushing the sides. The water is starting to look more clear. I saw some posts that said it could take a week to clean up the water (and some backwashes).

The good thing is that it looks like I'm making progress. My question is about something I'm reading in the manual with my Taylor test kit (K-2006) and it says I should superchlorinate to 30 FC to kill algae. Is this just their way to get your FC high enough to do the job without having to think too much about your CYA level, or are there reasons I would want to raise FC to 30 instead of 12 (CYA is currently around 30).

I didn't have noticeable algae on the walls (I'm sure the dark pebble finish makes it more difficult to see), but the water was murky and I had some "suds" forming on the top.

If I have no FC loss tonight, am I on the right track just keeping the filter going for a few more days (and backwashing) to finish, or are there reasons I should be trying to shock at 30 as Taylor's book recommends?

 

[PoolGuyNJ]

Please post your chem levels.

If you can run with the only wall returns, turn off the floor cleaning system. This will help let anything settle that is in suspension.

When was the last time the filter was cleaned? I don't mean backwashed. I mean opened, hosed down, inspected, and TSP soaked if needed.

Scott

 

[Red]

Scott...good thing you asked about the chemistry. First, I corrected my sig. My jets are deck jets, not floor cleaning jets. I added the Paramount canister when I replumbed last year. I get get a lot of debris in the pool from my pine tree. Pine needles clog the impeller. It's an added line of defense.

Anyhow, back to chemistry. I'd turned off my chemical system, so my pH was high from adding all the chlorine. I just turned it back on so it'll get the pH in line...at least that part works really well. Here's the latest results:

FC: 12.5 (no overnight loss)
CC: 0.5
pH: 7.8
TA: 110
CH: 325
CYA: <30

I'm surprised CC hasn't gone down to 0 after shocking. This makes me wonder if I need to shock at a higher FC? CC was 0.0 on October 30. Every time I've tested since then it's been at .5.

The Taylor kit doesn't measure CYA less than 30. I'm guessing I'm at 20? From the other posts I read, it said to keep CYA low to shock the pool, so I am. It was at 30 a few days ago. I've been having a problem with CYA dropping (which isn't helping the SWG, which probably let to my current mess). Fixing the CYA problem is my next problem after cleaning up the water.

The filter was last cleaned in August. I've never soaked my grids in TSP. I replaced 2 when I cleaned it.

 

[duraleigh]

Good morning, Red,

1. CC of .5ppm is treated as if it were zero. disregard it.

2. Normally only one overnight FC loss test is all you need but it sounds like you are doing it twice just to confirm your results. Correct?

3. Constant CYA loss might indicate a leaking pool with an autofill. Normally CYA can be brought to a given level and held there the entire swim season with maybe only 1 addition required.

4. I am curious where you saw the Taylor info about shock level 30ppm.

5. It sounds like you have everything progressing towards very clear water in the next day or so....nice work!! :lol:

 

[Red]

Yes, figuring out the CYA problem is my next challenge. I want to get the water fixed. I've seen a few posts about CYA drops.

The booklet that came with my test kit recommended 30ppm shock for algae. There's where I found it. I'm at work now, but when I get home I could reference the page.

I'm doing FC drop twice, as I saw a cloudy water post recommend you keep it constant for 2 days. Not much more effort to do it.

 

[Red]

Regarding the Taylor manual recommendation of 30 ppm FC (from Taylor part #2004B, p.36, discussion on cloudy water):

3. Algae Bloom: in incipient algae bloom will cause the pool to cloud. This cause of turbidity can be distinguished from others by a slippery feel on the pool's surface. Super-shock the pool to 30 ppm FC to correct this. Unfiltered dead algae will also cloud the water.

 

[duraleigh]

Hi, Red,

Thanks for posting that. I have not seen it before. Of course, you have probably seen the FC/CYA chart in Pool School wherein chem geek (and Ben, initially) developed a table of shock values based on CYA content.

Chem geek's table is actually much more precise than Taylor's in that an FC of 30 in a pool with no CYA could actually do some damage and may not be enough FC in an over-stabilized pool with very high CYA.