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DONNIE
12-03-2006, 01:59 PM
PH > 8

FC .5
CC 1.5
TC 2.0

TA 190

CH 70

CYA 0

SALT 0

I've got a good starting point and know I have to lower my Ph to the 7.5 range, add CYA to 30-50, get FC in 3-5 range , eliminate the CC, get my CH up to 300 for the heater. What about my TA at 190? Will it come down with my Ph? Then add salt to 3000 ppm for the SWG. I'm just questioning myself here. Any input is welcome.

Donnie

waste
12-03-2006, 05:39 PM
DONNIE, you've got the right idea. However, if you're going to use muriatic acid to reduce the pH, you might want to take the pH down to ~7.0 and airate off some of the alk. I've seen you around here and it looks like you know the drill, don't second guess yourself - I think you know what and how to do the things your pool needs. However, if you ever need a little advice - we are here to help you! - Waste:)

DONNIE
12-03-2006, 06:45 PM
I'm just wanting to get it right. Is a pH of 7ish acceptable? I do have a waterfall that will be installed next week. I'm sure that will help with the TA. I have went from 40 or so pages about water chemistry down to one over the last few weeks. I feel that I have a "pretty good" grasp on it thanks to this board and people like yourself. Now I just need to learn the difference in pink/red and how blue is blue. Thanks for the advice!

Donnie

chem geek
12-03-2006, 07:52 PM
What about my TA at 190? Will it come down with my Ph?
As waste says, you're doing fine and know what you are doing. If your pH were 8.4 (a guess, since you only know that it's > 8) and you added enough Muriatic Acid to get the pH down to 7.5, then your TA would drop from 190 to about 175. So though the answer is "yes" that the TA will drop along with the pH, you can see that it won't drop down very much. As waste says, the aeration at lower pH will get your TA down -- just remember that your pH will "fight" your wanting to lower it and will continue to drift up rather quickly (when starting at lower pH) until your TA gets lowered. That just means you'll be adding lots of acid over time. To accelerate the process, do the aeration (such as your waterfall) with the ph low as per Ben's Lowering Your Alkalinity (http://www.poolforum.com/pf2/showthread.php?t=191) instructions. So until you get your TA lowered, you can add acid to have your pH around 7.0 or whatever is just above the low end of you pH test kit.

Richard

DONNIE
12-03-2006, 07:58 PM
Thanks guys! That inital TA scared me. Now, can you tell me when blue is blue and not "blue" and when red is red and not "light red"?

Donnie

chem geek
12-04-2006, 01:51 AM
Thanks guys! That inital TA scared me. Now, can you tell me when blue is blue and not "blue" and when red is red and not "light red"?

Donnie
The TA test will go from green to red with a greyish color in between. I usually count the drop when it turns gray or red, but it's always within one drop so is not a problem.

It is the CH test where you go from red to blue and that is sometimes a difficult test to read because the blue won't stay blue if there is iron or copper in the water as the blue will turn purple and look somewhat red. To avoid this, add two drops of the titrant (hardness reagent) to the water sample before adding anything (e.g. before adding the calcium buffer). I always do the test this way (it is a recommended alternative from Taylor) and it comes out with a much easier to see endpoint transition. Be sure to count the two drops in the total count. Also, if you think you are at blue, but are not sure, just add another drop and the blue will be much more obvious. Again, the transition between the red and blue will be somewhat gray if you just happen to hit it exactly but the next drop will be a definite blue. I count either the gray or a blue as the end point, and again it's always within one drop so is not a problem.

Richard

DONNIE
12-04-2006, 09:07 AM
Thanks. That was my first time with a test kit so I was a little nervous.

Donnie

waterbear
12-06-2006, 10:01 AM
Now I just need to learn the difference in pink/red and how blue is blue. Thanks for the advice!

Donnie
The enpoints in the titration tests are very easy to determine. Just add drops until one more drop produces no more color change and then don't count that last drop. For example, with the TA test lets say that 6 drops produces a fleeting red color, 7 turns greyish, 8 turns greyish red, 9 turns red, 10 turns a brighter red, and 11 does not cause any color change at all. Your endpoint is 10 drops or 100 ppm TA.
Chemgeek gave you excellent advise on the calcium test (I do the same thing but I add 6 drops of reagent 1 before adding anything else--been doing calcium tests for many more years than I've owned a pool. It's a standard test for salt water aquairums and I've kept them for about 35 years now!). This will help deactivate any metals that might be present (the titrant in this test is a seqestering agent!) and help get rid of the 'purple floaties' that can make the endpoint of this test hard to see. Once again titirate (add drops) until one more drop produces no more color change and don't count the last drop. Once you get used to it the color change from purple (intermediate color) to light blue is pretty easy to see.
Same thing applies to the FAS-DPD chlorine tests. If you are not sure if the solution has turned colorless add one more drop and if there is no more color change don't count the last drop.

DONNIE
12-06-2006, 11:11 AM
Thanks. I have printed many of your previous post on testing methods and reading the results. You should compile them into a sticky. They are priceless!

Donnie

DONNIE
12-09-2006, 05:24 PM
Thanks to everybody! CYA is taking forever to dissolve with 50 degree water temps but the rest of my numbers are getting there.

PH 7.0
FC 5.5
CC .5
TC 6.0
TA 90 needs to come up a little
CH 130 needs to come up a little for heater
Didnt test CYA, have about 2# dissolved, hopefully 4# by Monday

I'm just so happy I had to tell someone!!

Donnie

(now if the PB will just get the sand off the bottom and the rest of the deck poured. Concrete scheduled for 9:00 Monday!)