Water change: Observations and Experiment

[windsurfdog]

Based upon observations that HotTubMan has shared here (thanks, HTM!) regarding pH increases being proportional to number of jets and jet action, I approached this water change a bit differently.  Mind you I am a relative hot tub neophyte having only installed and maintained my first tub since 7/11/04 and all knowledge gained has come from this and Doc's boards plus OJT gained since July.

We are blessed with excellent water out of the tap.....a municipal water utility that pumps excellent water from the Floridan Aquifer.  After filling the tub, here are the readings I took:
CH--170
TA--170
pH--7.3

After both the initial and 2nd water changes, I noticed that the pH would increase rather dramatically (+.7 or so points) in about 24 hrs. after the fill and initial readings.  Of course, after those fills, I then tried to counter with dry acid to bring the pH down to about 7.5.  This worked but I soon noticed that after a week or so the pH would slowly drop down to the 7.1-7.2 range which I would adjust with some sodium carbonate.  Of course, while all this adjusting was being done, I was adding more chems to the water.

24 hrs. after this latest fill, I found the pH to once again rise to about 8.0 - 8.1.  I resisted the urge to adjust with acid with the idea that the cyanuric acid in the dichlor I add after soaking and for shocking would bring the pH down to an acceptable level after a week or so.  Also, the water is just so darn beautiful and so foam free, I didn't want to add anything to it that wasn't necessary.

Yesterday, 9 days after the initial fill and after daily soakings with 1-3 tsp. dichlor afterwards and a single 3 tbs. dichlor shock, my readings were:
CH--170
TA--150
pH--7.5

So I have concluded that HTM's thoughts on rising pH are especially evident after a fill and this rise can be countered with dichlor use and time.  The water is still beautiful and foam free.  I'm sure continued additions of dichlor will cause the pH to slip over time and I'm prepared to adjust but I think my water will benefit from the initial "lack of adjustment" in the long run.

[Vinny]

WSD,

On a pool forum much like this forum they speak of lowering your alkalinity with aeration. Now a hot tub with it's jets is purfect for this, which is probably why your alkalinity is going down.

Also, in the Taylor kit they speak of some type of adjustment for CYA (I think it's alkalinity) and as your CYA goes up you need to adjust your other reading accordingly.

Your lucky to have great water out of the tap, my PH is usually 8+ and low CA and ALk.

Man, am I getting itchy for my tub!

[windsurfdog]

Man, am I getting itchy for my tub!

You need to pull the trigger, Vinny.......just pull that trigger!

[Vinny]

It'll be in the spring!

Put the deposit down on an Artesian Island Grand Cayman and the project is gonna be big - Electrical (200 amp service), tub, deck (nothing there now, thinking 16x24) and screen enlosure (possibly for the whole deck).

Moved into the house 4 1/2 years ago and haven't painted the kids rooms yet - LOL. House is 35 YO and NEEDED (still needs) a lot of things done - I promised the kids they come first before the tub!

[Brewman]

But just think of the sore muscles you'll get doing all that painting and other work.   I think you'll do a better job if you have a spa to help you relieve those sore muscles, so in a way, getting your spa first will ultimately benefit the kids.
Brewman

[Chas]

But just think of the sore muscles you'll get doing all that painting and other work.   I think you'll do a better job if you have a spa to help you relieve those sore muscles, so in a way, getting your spa first will ultimately benefit the kids.
Brewman

When daddy's happy, everbody's happy !!!  

[Vinny]

Brewman,

I used that excuse to get the tub in before renovating my 2 bathrooms - I guess those will be in the summer and fall of 2005.

I have good kids - they deserve something. It must be embarrassing to my 14 YO to live in a constant construction zone - all his friends have been in the neighborhood since birth so they're established.

Chas,

Your ABSOLUTELY WRONG - When MOM's happy, then Dad's happy and so is everyone else! LOL

Vinny

[Chas]

Chas,

Your ABSOLUTELY WRONG - When MOM's happy, then Dad's happy and so is everyone else! LOL

Vinny

I sit corrected !

[salesdvl]

We are blessed with excellent water out of the tap.....

I always perfer excellent BEER out of my tap.  

[windsurfdog]

 I always perfer excellent BEER out of my tap.  

I'll drink to that.........

[Drewski]

Hey Vinny!

Ya gotsa get yooz a tub so yooz can swim with the rest of us fishes...

SORRY buddy, I just can't help it!

Here's a picture of my last deck for ideas (click to enlarge). Note where the tub used to be. Took me about 2 months of weekends to do the work by myself. All in all, it turned out good...

Drewski

[wmccall]

I sit corrected !
 

Isn't it time you get up and move around a bit? Go do some Christmas Shopping, the family won't accept scent packets from your store this year! The baby can't use PH Down in her diaper!

[Chas]

Isn't it time you get up and move around a bit? Go do some Christmas Shopping, the family won't accept scent packets from your store this year! The baby can't use PH Down in her diaper!

Why would Christmas shopping involve getting up from the computer???

I don't get it.

And for those of you who are new to this forum:

DO NOT USE pH DOWN IN A BABY'S DIAPER!! BILL WAS TRYING TO MAKE SOME SORT OF JOKE.

You'll have to forgive him, I make it look easy. Actually, it's pH UP !!

[stuart]

Why would Christmas shopping involve getting up from the computer???

I don't get it.

And for those of you who are new to this forum:

DO NOT USE pH DOWN IN A BABY'S DIAPER!! BILL WAS TRYING TO MAKE SOME SORT OF JOKE.

You'll have to forgive him, I make it look easy. Actually, it's pH UP !!

 

Doesn't Baqu make something for that?  

[Chas]

Doesn't Baqu make something for that?  

LOL LOL LOL