water too high - drain it down?

[doncaruana]

Here in southeastern Michigan, we have been getting absolutely hammered with rain. Right now, my water is actually so high that it's above the cavity opening for the skimmer, as in maybe an inch from the bottom of the coping.

I know if I pump some off, I'll lose some chemical value. But, other than skimmer effectiveness (i.e. none, but it's not that great under the best of circumstances anyway), is there some chemical or otherwise factor that would drive me to lower this now, vs let mother nature lower it via evaporation?

Also, I'm still putting off needing to shock this pool (it seems to have a very high chlorine demand, but CC are low and the water is clear). How would that play in to the water level?

 

[Charlie_R]

Yes, drain to the middle of the skimmer. You won't lose that much chemical value. Check Poolcalculator to see how much.

Do you have CYA in your pool? How much? Is it enough of an FC demand that our Intellichlor can't keep up?

 

[doncaruana]

CYA is at 50 but I have the IC40 at 90% for now running 10 hours a day (used to be at 30-40% and this is only its 2nd season). That seems to be just barely enough when last I was able to check (slowly rising FC). But, even though my CC are consistently below 0.5 (I do the 25ml bigger test, so I get 0.2 or 0.4 for CC), when I checked a couple of days ago, I lost 1.6 FC overnight.

 

[Charlie_R]

Then yes, it's time to start the shock process. Bring your pH down to around 7.2, and shut off the IC40. While you are shocking, you might want to clean it.

Could you post a complete set of test results?

 

[doncaruana]

I've been holding off because it was so hot (family request ). Also been seeming to have difficulty getting the pH down despite the pool calculator's numbers. I don't think at 4-7 FC that would affect the pH readings that much would they?

 

[Butterfly]

I've been holding off because it was so hot (family request ). Also been seeming to have difficulty getting the pH down despite the pool calculator's numbers. I don't think at 4-7 FC that would affect the pH readings that much would they?

No, any FC below 10 is good for the pH test.

You can follow the shock process and still let folks swim. The pool should be brought to shock level not less than twice per day, so you could do morning and night.
You could prob get more than one test/add in at night. pool-school/shocking_your_pool

After the morning shock, it won't take long for the sun to lower FC below normal shock level and let 'em swim.
It is safe to swim at normal shock levels, too.

Rinse off before and after, as folks should be doing anyhoo.

 

[Charlie_R]

Just curious, what test kit do you have?

 

[doncaruana]

Just curious, what test kit do you have?

TF-100

 

[Charlie_R]

Could you please post a full set of numbers? I'd like to check my thinking on something.

 

[doncaruana]

These are from yesterday morning, between one inch rainfalls:
FC 6.2
CC 0.4
CYA 50
pH 7.6
CH 90
TA 120

 

[Charlie_R]

Ok, thanks. What I was thinking was maybe your CH and TA were possibly high. Since those are looking ok, the only thing I can think of with your pH not wanting to come down is the IC40 driving it up.

I assume that you haven't been using any powdered chlorine products, since your CYA is good.

Yes, I'm still somewhat of a noob, and learning as much as I can. I learn best by trying to help others in their quest for a sparkling pool.

 

[doncaruana]

Ok, thanks. What I was thinking was maybe your CH and TA were possibly high. Since those are looking ok, the only thing I can think of with your pH not wanting to come down is the IC40 driving it up.

I assume that you haven't been using any powdered chlorine products, since your CYA is good.

Yes, I'm still somewhat of a noob, and learning as much as I can. I learn best by trying to help others in their quest for a sparkling pool.

TA is higher than recommended and I might be fighting that a bit. But chlorine has come only from the SWG and one bottle of 8.25% bleach.

 

[pwrstrk]

With a SWG your CYA should be alittle higher. 60 to 80 ppm.


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[doncaruana]

With a SWG your CYA should be alittle higher. 60 to 80 ppm.


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Yep - I know. It was there earlier this month and suddenly dropped 20ppm over the course of about 2 weeks (or less). I've been vehemently told that's not possible, but I assure you it is.

 

[pwrstrk]

Wow that's a pretty good drop. Do you have any idea why, or has anybody given you a reason why ? Maybe all the rain ?


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[Charlie_R]

Missed that, sorry. Not having one myself, I'm used to keeping CYA between 30 and 50.

What is the total amount of rain you've gotten in the last month?

Right after I put up our pool, and had it stabilized, we received storm after storm, with a total rainfall of close to 12" in 3 weeks. I had my CYA at 50, the rain dropped it to it's present level of 30ish. Reminds me, I need to get another puck to bring that back up a bit (knocking sense back into my head!).

 

[doncaruana]

Since this happened, we've had maybe 6 inches of rain, but in 2 massive downfalls over a couple of days each time. From all the reading, I'm convinced I had some bacteria that went nuts and attacked the CYA before I cranked up the chlorine and held it at bay. Doesn't matter too much now...just have to get it back up

 

[pwrstrk]

If you think you have something going on turn off the SWG and just use bleach to shock. Might not hurt to shock now with the CYA being lower. The shock level will be lower with the lower CYA level.


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[doncaruana]

So, incidentally, when I tested the water this morning, I had 5.8 FC and zero CC. So I had 6.2FC, pumped in 4.2 via my SWG (total of 10.4) and lost 4.6 in 24 hours of no usage and a couple of inches of rain. Yet I have no CC.

Seems really weird to me...