Heavy rain forecasted...what to do?

[0REDSOX7]

Hello fellow pool friends.

This week, they are forecasting around 4” of rain for my area. Given I only have an 18’ round by 52” deep pool - what should be the best course of action here.

Obviously a pool cover will be useless since there is no way to get it off without all that water mixing.

Is it best to shock it before hand or just let it dilute and deal with it after the fact? Obviously a big hit to chemistry will be in order - but, just trying to see what the best plan would be.

I thank you in advance.

 

[mknauss]

4 inches of rain will have little effect. Either drain down a bit or be prepared for it to overflow.

Maintain FC and test pH once the rain is over.

 

[YippeeSkippy]

It wouldn't hurt anything to add a bit of extra chlorine in the water today or tomorrow since you know you're up for days of rain but its not really necessary.
Rain doesn't do anything more than dilute, and you'll overfill possibly. You could drop your water level an inch or two in advance if you want.

 

[Saturn94]

There’s no harm bringing it up to SLAM level before a big rain hits. It may give you some peace of mind. ?

 

[Donldson]

I think you are overestimating the severity of this a bit. 4 inches of rain in to 48 inches of water is only 8%. Measurable, but not very major.

 

[Richard320]

Siphon off a couple inches to make room and bump FC a couple points to deal with the debris that is sure to end up in there.
4" is less than 10% of your volume. So you'll lose 10% of Salt, TA, CH, CYA. It might not even be measurable depending on where you are now. Lose 2", Gain 4", and wait for it to evaporate back and it's only 5% change.

pH tends to rise with the aeration that heavy rain creates on the surface.

 

[Andrew Pumariega]

Hello fellow pool friends.

This week, they are forecasting around 4” of rain for my area. Given I only have an 18’ round by 52” deep pool - what should be the best course of action here.

Obviously a pool cover will be useless since there is no way to get it off without all that water mixing.

Is it best to shock it before hand or just let it dilute and deal with it after the fact? Obviously a big hit to chemistry will be in order - but, just trying to see what the best plan would be.

I thank you in advance.

Hi 0REDSOX7,

If you're expecting 4 inches of rain I wouldn't worry at all. If you want to err on the side of caution, add a little extra chlorine.

As for draining some water out of your pool, that's not necessary. Just imagine a concrete patio covered the surface area your pool occupies. The exact same way the rainwater would react to your hypothetical patio is the exact same way the rain will react to a pool that is 100% full. An overflowing pool does not cause flooding. Too much rain causes flooding and your pool holds no bearing on that.

Also, if you put a 100,000-gallon pool side by side a 10,000-gallon pool, they will gain the same amount of rainwater in terms of inches, however, not gallonage. This, of course, assumes neither pool is getting any runoff rainwater. So the fact that your pool is small, does not matter.

You should be good.

 

[0REDSOX7]

Thank you all for the piece of mind. I’ll add some extra chlorine tonight.

 

[Rich D]

I would never underestimate mother nature in these types of events. if there was not proper grading and drainage installed for the pool, a overflowing pool can saturate areas that are not typically saturated and cause shifting, settling and erosion. It would be safest to not allow the pool to overflow. I would drain it down a few inches and have it set up so you can easily drain more during the storm event if needed as well. keeping in mind that most power outages come with these type of storm events.

 

[setsailsoon]

We get that kind of rain several times per year. Like most people here I'd just bump up the FC a little. Other than that keep an extra gallon or two of liquid chlorine on hand in case the power goes off.

 

[0REDSOX7]

I will plan to lower it a few inches today. Thankfully, the rain will not be all at once, but starting tonight and ending around Friday - so, I'll be able to monitor it in between downpours.

I bought 13g of liquid chlorine before the season started in an effort to not run out - hopefully that will hold me over since it seems hard to come by these days - especially with COVID going on...

 

[YippeeSkippy]

well, just so far we've had *a mess* of rain here in Georgia.... wet till Friday.