We had 9.5" inches of rain last night

[tstex]

Hello to all,

If you have seen the news w flooding in Texas, Houston took 4-5" on the low side, 10-12" on the high; we got 9.5"

I could never go to sleep, so I periodically turned on the outside light and looked at the pool to see if it was overflowing. Since I always saw the bull-nose on the coping, I would say it did not overflow, but w 9+ inches of rain, a lot of rain water mixed w pool water and flowed out the drain.

The pool is chorine-based and is about 15Kgal w Spa. 3.5-4.5 & 5.5' deep and daily temps are low 70's to mid-80's, pool water is 79-80 degrees. The water is not crystal clear like usual, and has a tint of opaqueness to it. There is not a lot of debris in the pool except a few pieces of mulch and a few earthworms. The skimmers have hardly had anything inside them.

I have been running the pump since 7am and the Robotic QC Shark for the last 4 hrs and it looks like it has cleared a bit, but that could have been bc there was no sun early am.

So, what are the usual results of a lot of rain-water and what impact do they have on pool chemistries / water clarity? If you have any other questions, pls let me know?

Thank you very much,
tstex

 

[Patrick_B]

Usuall very, very little.

But, 9.5" is a lot of rain, so I am very surprised it didn't overflow. Do you have a overflow just above the waterline?

based on what you say here, I would up the FC level if it was my pool for sure. Sounds like some surrounding washed in and you want to make sure you are covered. What is the FC in the pool after this event?

 

[robbief00]

I'll share my experience since I am in the same area, same size pool, periodically checked on it all night, rain filled up to coping (even with an overflow drain), chlorine-based, etc...

My pool was crystal clear blue last night with good FC level but woke up this morning to a slightly cloudy, green tinted pool. It was still clear enough to see down to the drains at 5.5 ft. I added enough bleach to bring it up to shock level and have been running the pump all day. It turned blue again fairly quickly but still not as crystal clear as usual.

This is a fairly new pool and my first experience with algae but I guess I caught it early enough for it to really take hold.

From what I have read on here, normal rain should not affect the chemistry of the pool much at all....but its possible the amount we got in Houston last night was an exception to the rule. I also understand that lots of lightning (like we had) causes nitrogen in the atmosphere that gets washed into the pool allowing small amounts of algae to multiply much quicker than usual.

 

[Divin Dave]

well first of all, Im glad y'all are all ok. Still waiting on some other Houston folks to tune in though.

Considering the circumstance, sounds like everything is for the most part fine. Wont hurt to do like you're doing and bump up the FC to SLAM and keep it there until
CC is less than .5 (one drop to go clear)
You pass a OCLT
Water is back to crystal clear

We only got 5 inches here in NE Texas where Im at last night, but I did have to dodge quite a few lightning bolts! (again).

 

[Texas Splash]

We got pounded here around San Antonio. I'm currently SLAMming just because my FC/CC levels are on the boarder-line and I thought I saw a small bit of junk in the pool. The past few weeks have lowered my CYA and caused my to be more vigilant on my FC. Aside from that, it's time for a dip. Happy swimming!

 

[tstex]

I'll share my experience since I am in the same area, same size pool, periodically checked on it all night, rain filled up to coping (even with an overflow drain), chlorine-based, etc...

My pool was crystal clear blue last night with good FC level but woke up this morning to a slightly cloudy, green tinted pool. It was still clear enough to see down to the drains at 5.5 ft. I added enough bleach to bring it up to shock level and have been running the pump all day. It turned blue again fairly quickly but still not as crystal clear as usual.

This is a fairly new pool and my first experience with algae but I guess I caught it early enough for it to really take hold.

From what I have read on here, normal rain should not affect the chemistry of the pool much at all....but its possible the amount we got in Houston last night was an exception to the rule. I also understand that lots of lightning (like we had) causes nitrogen in the atmosphere that gets washed into the pool allowing small amounts of algae to multiply much quicker than usual.

This is exactly where I am...same diagnosis...I did not have my test kit w me, but will Thur. How much bleach did you add ? Was it gradual or all at once?

Yes, lightening can really fill the air w Nitrogen and the rain brings it down -great for grasses and other and that's was really "greens-it-up".

And to answer prior question, drain is right above waterline. Four drains on the pool deck and they worked well.

Appreciate the follow-up, tstex

 

[armsdealer]

My PH is way up and FC was way down after all the rain. I added bleach, I guess I am going to have to add some HCL to lower PH

 

[robbief00]

How much bleach did you add ? Was it gradual or all at once?

I typically use 121 oz jugs of 8.25% bleach. Pool math said I needed about 1.3 jugs to bring it up to my shock level for my current CYA value. I pour it slowly in front of a return. After testing again yesterday evening, I needed to add another full jug. I did the OCLT test last night and didn't lose any chlorine, pool is clear again, and CC is zero so I can let it come down to normal chlorine levels. Without your test kit, it is hard to say how much bleach you really need.

 

[JayBauman]

So, what are the usual results of a lot of rain-water and what impact do they have on pool chemistries / water clarity? If you have any other questions, pls let me know?

Howdy, neighbor. Based on comparison of pre-rain and post-rain chemical analyses (Thanks, TF-100!!!), I got 9-10" at my house Sunday night (and probably a total of 14" over the last week!). My overflow drain was losing the battle, but it did drain enough to keep the water within the pool walls. My water got a bit cloudy, but I attributed this to the dirt that had washed into my pool...my main evidence being all the dirt that I have since hosed off my decking back into my flowerbeds and yard. Due to holiday weekend pool parties and anticipation of heavy precipitation, I had elevated my chlorine level before the rains came. After a day of running my cartridge filter, the pool is once again crystal clear. Other than having to add salt, CYA, and calcium to bring my chemistry back to my goal points, my pool is no worse for wear...even though the rain has exchanged about 30% of my pool volume this week!

 

[tstex]

Morning Jay,

Yes, its been one heck of a ride with these rains, and we are getting more now and they predict another major event this weekend w 4-6" more on the way.

I added two cups of bleach to 3 gallons of H20 in a bucket last evening and tossed her in...then ran the pump for 4-5 hrs and it's looking almost perfect this morning. I will get my TF-100 test kit back this evening and do all the tests and post. I am thinking a little MA to lower pH will be on the menu. Having one of my daughters b-day party tomorrow at 5pm, so it has to be right. Hope the lightening is gone.

Ever since I bought my ranch 21 yrs ago, I have been a major weather/radar monitoring activist. Have to always determine will I need to spend the weekend watering or not? I much rather have these excessive rains than ever experience the 2011-12 drought again. Speaking of rains and pools, I know a PB that works the F-Bend, Harris and Montgomery counties that has a backlog of 29 pools. You just cannot dig a pool when you sink the b-cat or sink the plywood too that you laid from the excavation site to the dump truck...cave-ins are real costly too.

Keep in touch and good luck out there,
tstex