Quandry: Pool chemical balance

[pkassoc]

current pool parameters are as follows:
FC .5
ph less than 7.2 (off the color scale)
TA 160
CYA 60
pool temp 60F
new water this summer; water from tap is neutral with TA of 10
have not added acid for months for obvious test result reasons

If i add acid to lower to TA, the ph will be even lower...if i add soda ash to get the ph up, the TA will go up.....have no idea what to do.

 

[Guest]

aerate the water to bring up the pH without affecting TA (by gassing off CO2). These threads might be helpful to you:

how-to-lower-ta-t5341.html

ta-what-is-it-really-t4979.html

Also, borax will raise pH with minimal impact on TA (and borates are a useful addition to any pool for various reasons).

 

[duraleigh]

You don't say where you live, but with a water temp of 60 degrees, you're somewhere pretty warm. You need more FC in your pool to prevent algae and other contaminants......around 3-5ppm based on your CYA of 60.

Balancing your pH and TA is important but do not overlook your need for FC.

 

[pkassoc]

thanks everyone very much for the guidance.. :-D

Had no idea that aeration was a process that even existed....very naive....however, i have a clue from your suggestions...I have a solar pool cover that i have left on year round and i suspect any outgassing of co2 may be highly prevented by this cover...I have used the cover to reduce evaporation and keep a lot of dirt out of the pool..It may be possible that if i remove it as well as using the borax suggested i can reduce TA and raise the ph to where it should be. If this will have no effect or something else is recommended, please let me know.

I can also route the return thru the spa to aerate.

 

[chem geek]

thanks everyone very much for the guidance.. :-D

Had no idea that aeration was a process that even existed....very naive....however, i have a clue from your suggestions...I have a solar pool cover that i have left on year round and i suspect any outgassing of co2 may be highly prevented by this cover...I have used the cover to reduce evaporation and keep a lot of dirt out of the pool..It may be possible that if i remove it as well as using the borax suggested i can reduce TA and raise the ph to where it should be. If this will have no effect or something else is recommended, please let me know.

I can also route the return thru the spa to aerate.

You aren't naive. The pool and spa industry doesn't educate its dealers very well -- even the education with certification (e.g. NSPF CPO, APSP TECH) doesn't cover everything and is incorrect or misleading about some things (such as the relationship of chlorine and CYA).

You are absolutely correct that using a pool cover will tend to prevent outgassing so that is probably why your pH hasn't been rising or more stable. What are you using as a source of chlorine in your pool?

If you remove the cover, then unless you are using an acidic source of chlorine (such as Trichlor), then the pH may rise. Aeration simply accelerates this so yes, if you route through the spa with aeration jets, then that will speed up the process of raising the pH. If you do this, then you won't need to add the Borax. Since your TA is higher, I'd suggest the aeration to raise the pH instead of the Borax, just so you don't increase the TA anymore. Using Borax to raise the pH still increases the TA, but only by half as much as using a pH Up (sodium carbonate) product. Aeration will raise the pH with no change in TA at all.

Richard

 

[pkassoc]

i have been using trichlor exclusively and i felt that MAYBE the high cya reading of 60 was causing my ph readings to be artificially low. Some other source said that cya should never be above 30 ppm. Is this a valid upper limit? Should i dump some of the water to get down there?

I am located in Hunt Bch ca. and with the cover the temp doesnt drop much. Will take the cover off and aerate thru the spa overflow and repeat measurements until i get stability in readings. The spread sheet that shows chem treatment required that you have on this forum will be used from now on to the keep this pool steady.....

 

[chem geek]

i have been using trichlor exclusively and i felt that MAYBE the high cya reading of 60 was causing my ph readings to be artificially low. Some other source said that cya should never be above 30 ppm. Is this a valid upper limit? Should i dump some of the water to get down there?

I am located in Hunt Bch ca. and with the cover the temp doesnt drop much. Will take the cover off and aerate thru the spa overflow and repeat measurements until i get stability in readings. The spread sheet that shows chem treatment required that you have on this forum will be used from now on to the keep this pool steady.....

It's not the CYA level, but rather the use of Trichlor that causes the pH to be low. Trichlor is very acidic upon addition and then the usage/consumption of chlorine is also acidic so it's a double whammy. Normally, you keep the TA higher when using Trichlor, but this only helps to stabilize the pH if you don't have a pool cover since one purpose of the higher TA is to increase the rate of carbon dioxide outgassing from the pool as that will raise the pH helping to compensate for its getting lowered by use of Trichlor. Over time, if one has this balanced out correctly, the pH is fairly stable and only the TA drops whereby you add baking soda to raise it. Alternatively, at a not-as-high TA level one could periodically use pH Up (sodium carbonate; Arm & Hammer Super Washing Soda) that raises both the pH and TA.

At any rate, your continued use of Trichlor will likely continue to increase your CYA level and that may lead to problems such as algae growth unless you do one of these things: 1) raise your FC target as your CYA level climbs, 2) use a supplemental weekly algaecide (PolyQuat 60) or phosphate remover at extra cost, 3) switch to using unstabilized chlorine (usually bleach or chlorinating liquid). The latter approach is what most people do on this forum -- it's the least expensive way to go but does usually require more frequent chlorine addition. However, with your use of a pool cover, you may find that you can add chlorine 2-3 times a week rather than every day. In my pool, the cover is an electric opaque safety cover so chlorine usage (in the summer) is low at 1 ppm FC per day even with the pool used every day so I add chlorine about twice a week.

Be sure and read up at the Pool School on this forum. And welcome to Trouble Free Pool!

Richard