Rainwater

[hot tub Frank]

After a nice rainfall i got a few gallons of rainwater in my tub.
the result is that my TA and PH took a nose dive.
Is this normal ?

[Silent Water]

Absolutely!  Even my pool's pH is affected after a prolonged downpour.  Just goes to show that acid rain really is a problem.

[hot tub Frank]

So! Is rain now good or bad water???
I know now that it will affect the tub.

[lskarp]

You are looking at adding water to the spa which is not sanitized and has been falling through the air.  If you lived in Los Angeles, it woudl be worse than say, the middle of nowhere because of the particulates, etc.  

I woudl imagine that you will need to adjust the PH and add sanitizer to bring everything up to normal levels.  The % of the total water added can get up there pretty quickly as the spa only has a couple of hundred gallons to start as compared to a 20,000 gallon swimming pool.

Maybe go to your normal weekly shock routine, I am sure it will balance out.

[drewstar]

How did the rain water get into the tub? I assume you have a cover? Were you soaking in the tub while it was raining? I tried that once and didn't find it very comfortable (cold rain in my face and hair,   ).  But I agree rain water, although it "sounds" nice may not be as clean and as pure as you'd think.   But could a few gallons throw off  tub? Can  2 -3 gallons of unbalanced water added to 400 gallons make a measurable difference?  With a pool I could see it being an issue (There's a lot more rain entering a complelty uncovered pool.

We got some very nasty storms here in MA on saturday.  High winds (50 mph) and heavy, heavy rain. Sunday morning, the rain subsided, but the winds were fierce. I took a quick soak and the wind was whipping across the tub and spraying the waterfall into my face. I never had that happen before.  

[Bama]

Not that Trixie really knows, but it seem would  that rain water throwing off the ph is no different than adding fresh water from the faucett.  Either way one must use chemicals to adjust, right?   As far as soaking during the rain...Trixe has done that and  thought it was  sexy!!!!   The lightening bolts can be a little tricky!  

[lskarp]

A couple of gallons of rain, probably cool.  But my untrained opinion is that rain would cause more 'harm' that faucet water because it is totally untreated.  Most city water is Ozonated, chlorinated, and mony other nateds and filtered, etc.  

If it rained hard and added 10 gals for example, you are looking at 2.5% of the total volume.  in a pool, you would need some 250gals to equate.  Also, because a pool is deeper, less of the surface is exposed as a function of the total capacity.  

[In Canada eh]

If it rained hard and added 10 gals for example, you are looking at 2.5% of the total volume.  in a pool, you would need some 250gals to equate.  Also, because a pool is deeper, less of the surface is exposed as a function of the total capacity.  

lskarp and Hot Tub Frank

         This is very common,  if we get a good rain shower I can pretty much just go add a cup of pH up to my pool without even testing the water.  Rain can also have a effect on the alkalinity sometimes

[Vinny]

I would say adjust the PH and alkalinity and shock the water to kill any bacteria spores that might have been carried into the spa ... that is what you do to a pool after a heavy rain.

[hot tub Frank]

At least trixi understands the need. even if she does not know much about the chems.
But trixi has a very good point!!!!