Minimum FC question

[sunpole]

Currently my pool has 50 CYA, and I aim for 6-7 FC every night, but I lose about 4 FC during the day to the sun, so by the time I get home my FC is usually around 2.5-3, which is lower than the minimum of 4. Question is do I have to raise my FC to so that at no point in time my FC is lower than the minimum? Or dipping below the minimum for part of the day is totally fine?

 

[mknauss]

Raise your target level so that you never go below minimum.

 

[Jimrahbe]

sp,

It would not hurt you to raise your CYA to 60 to help with the FC usage during the day..

Also, if you let your FC drop below your minimum, you might already have an algae bloom starting. I recommend you run an Overnight Chlorine Loss Test, just to make sure.. See this link... Overnight Chlorine Loss Test

Thanks for posting,

Jim R.

 

[React]

sp,

It would not hurt you to raise your CYA to 60 to help with the FC usage during the day..

Also, if you let your FC drop below your minimum, you might already have an algae bloom starting. I recommend you run an Overnight Chlorine Loss Test, just to make sure.. See this link... Overnight Chlorine Loss Test

Thanks for posting,

Jim R.

Jim - Where in Bedford are you? My parents (house I grew up in) are off Cheeksparger and Martin. Small world!

 

[sunpole]

sp,

It would not hurt you to raise your CYA to 60 to help with the FC usage during the day..

Also, if you let your FC drop below your minimum, you might already have an algae bloom starting. I recommend you run an Overnight Chlorine Loss Test, just to make sure.. See this link... Overnight Chlorine Loss Test

Thanks for posting,

Jim R.

Thanks for the tip Jim. I test my water 3 times a day, once around 5pm, once 7pm after adding chlorine, again in the morning around 7am.

Here is my # from the last week average,

5pm 3ppm
7pm 7ppm
7am 6.5ppm

I think I'm gonna put the tabs back in there to help the CYA and FC, at the same time bring my FC up to 8ppm every night.

 

[Jimrahbe]

R,

I'm pretty sure that I don't live in your parents house, as my dad and I built my house over 30 years ago...

I'm off the intersection of Central and Harwood... pretty close to your parents house..

Thanks.. Now I'll have that darn song stuck in my head for the rest of the day...

Jim R.

 

[tomfrh]

Stay above the hard deck! Or risk a crash and burn.

 

[Arizonarob]

Sunpole, you lost 0.5 ppm overnight according to your numbers. Jim is right in the fact that you may be in the early stages of an algae bloom. You might want to bring your FC up to SLAM level, and do another OCLT.

 

[sunpole]

Sunpole, you lost 0.5 ppm overnight according to your numbers. Jim is right in the fact that you may be in the early stages of an algae bloom. You might want to bring your FC up to SLAM level, and do another OCLT.

I don't think I have an algae problem yet. Did careful OCLT test for 2 nights, both nights FC holds up with close to 0 loss. And yesterday we had an overcast day, my daily FC loss was only 1.5... However, I do have some concern with my CC been around .5 for a while, it used to be zero. Does this mean I have some organics in the water?

 

[Arizonarob]

.5 CC shows that something organic is in the water that the chlorine is chomping on. Before you raise your CYA up, I would bring your pool up to SLAM level.

 

[sunpole]

.5 CC shows that something organic is in the water that the chlorine is chomping on. Before you raise your CYA up, I would bring your pool up to SLAM level.

Do like a proper slam? I mean my pool technically passed all the test, sparkling clean, overnight test and CC less than 0.5. Do you think a proper SLAM will bring the CC down to 0? I just don't want to spin my wheels.

 

[Arizonarob]

Well, your post stated that you lost .5 overnight in FC. So if you did, then there is something living in the water. Just to play it safe, I would bring it up to SLAM level according to the FC/CYA chart, brush the walls, steps, etc, and run the pump overnight. Then just let the chlorine fall back naturally.
Make sure when you do the OCLT, that you test in the evening when there is NO sun on the pool, and again before the sun hits the pool in the morning.

 

[jblizzle]

A 0.5ppm loss over night is well within passing the OCLT (and they started early at 7PM and ended late at 7AM).
A 0.5ppm CC is also generally not something to worry about.

You could certainly bump up the FC a little bit high one night to help clear up the CC, but no reason to need to do the SLAM process from what I have seen.

 

[Poolzzz]

Well, your post stated that you lost .5 overnight in FC. So if you did, then there is something living in the water.

Not true on both accounts.

FC consumption is not limited to living things. It can occur due to oxidation of any number of things...sweat, sunscreen, bubble covers, even CYA.

Also the OCLT pass limit is 1ppm, not 0.5 ppm. So 0.5ppm loss is not a reason to SLAM. It is the smallest unit we measure so rarely a reason to get excited.

A CC of 0.5 is not much a concern either. A SLAM is considered successful with this level. There are many reasons one can have a CC of 0.5 that are benign. I'd agree with bumping the fc a little might help clear it or if you have a cover take it off for a bit.

The original suggestion to do an oclt was because the fc had dropped below minimum. Since the oclt is now done multiple times and passed easily plus all SLAM pass criteria are being met I don't see any reason to do anything except enjoy the pool.