Rainwater harvesting and TA

[karmabiker]

I'm following Richards approach to CA scale and am harvesting rainwater. My first test after harvesting revealed a TA of 50 (down 40%). I'm curious as to others experience with rainwater harvesting, asphalt shingles, and the overall effect on TA. Based on the CYA and CH dilution my first harvest replaced 25-30% of the pool water (WOOOHOO).

As always thanks for the help guys!

 

[Smykowski]

I use a kneehigh rubberbanded to the end of the tube to catch any grit from the roof. I also use corrugated tubing, which helps catch stuff along the way.

As to chemical variations, catch some rainwater from the tube and test it. That will help you plan for the minor adjustments after it rains.

 

[Patrick_B]

That is an amazing amount of water to capture. Rain water has little of anything in it, so you should expect to see a reduction in everything including TA. That is a really impressive amount of reduction.

 

[karmabiker]

It was a proper gully washer. The catchment coming off of the roof looks like a firehose ... 4 or 5 hours of that.

 

[karmabiker]

I was surprised by the volume, the bigger surprise was the TA dropping more than the rest of the chemistry.

I'll grab some water coming off the roof next time to see what the levels are.

 

[Patrick_B]

It will be little TA and CH. Pure rain water won't have either, anything that it does have will be from contact with surfaces and substances it encounters. When water evaporates, everything solid (dissolved or otherwise) is left behind.

 

[Richard320]

I wish I could get enough rain to make a significant difference in things.

The shingle grit doesn't seem to mess with the chemistry or stain the plaster, but it is a bear to vacuum up.

The TA could have dropped some because of the aeration the rainwater did to the pool. When the surface looks like it's boiling, you know that's got to count as aeration!

 

[Patrick_B]

So do I!

However, at less than one inch for 2014 so far, it's a good thing I'm not counting on it.

 

[karmabiker]

Got missed by the last set of small rain clouds in the Houston area. Looks like I may have to give in and use city water to bring the level up a wee bit. I hate adding CH...

Richard, Does aeration actually impact TA? I was under the impression aeration moved the PH and acid moved TA and PH.

HAPPY FRIDAY!!!!

 

[Richard320]

Got missed by the last set of small rain clouds in the Houston area. Looks like I may have to give in and use city water to bring the level up a wee bit. I hate adding CH...

Richard, Does aeration actually impact TA? I was under the impression aeration moved the PH and acid moved TA and PH.

HAPPY FRIDAY!!!!

you are correct

 

[mas985]

Rainwater is rarely pure and rarely inert even before it hits the ground. Clouds form from vapor condensing around small particles in the atmosphere and as rain falls it collects even more particles that are suspended in the air. So technically, it can contain almost anything suspended in the atmosphere including pollen, mold spores, bacteria and smog which may even add to the chlorine demand. Sometimes I notice a larger FC drop after it rains.

http://www.nasa.gov/centers/langley/news/factsheets/Aerosols.html

http://www.popsci.com/science/artic...here-might-affect-cloud-formation-and-climate

 

[karmabiker]

Great article - thank you!

 

[karmabiker]

Grrrrrr. Looks like I may have to add city water, Holding out till thursday and the skimmers are off ... main drain only. WE NEED RAIN. And I'm obsessed with my CSI.

thanks for listening.

back to your regularly scheduled programming.

 

[YippeeSkippy]

I would love to see pictures of how y'all are collecting this rainwater into your pools? <pretty pleaseeeeeeeee!>
Yippee

 

[karmabiker]

And the water level this morning...

The radar ...

Fingers crossed

 

[karmabiker]

It would seem that there is a large umbrella over my house. Lots of rain around ... just not here.


grrrr

 

[karmabiker]

It seems there is hope for rain.

Numbers pre rain:
Ch 550
TA 50
Ph 7.5

 

[bridgman]

I nearly hurt myself laughing when I saw this. Reading from the front of the thread, I had imagined diverters, plumbing, big cisterns to hold the water, and pumps to get it into the pool. That's a great setup, and about 500x simpler than what I had in mind.

 

[karmabiker]

Glad I could put a smile on your Friday!

I've got plans for a diverter and a removeable section that goes straight to the spa. It's a little lower priority than some other projects...

 

[karmabiker]

Finally some rain.

The TA coming off the roof is probably 0 - It turned on the first drop

The Ph is 7.2

No real point in testing anything else, no CH no CL and no CYA unless something has gone horribly wrong in the atmosphere.