Need Help With Chemistry

[vschuel]

This is my first venture into the world of backyard pools, so please forgive my ignorance in advance. I have a 10' x 30" pop-up pool. I have been having NOTHING but trouble getting the water balanced. The last time I tested my water, my pH was around 6.8. I then tested my TA, and it was about 120. I proceeded to adjust the pH by adding hTh pH Plus. This morning I checked pH again and it was in range at 7.2, but TA was 160!!! I have been using 1" PACE trichlor tabs. Also, I have been noticing this grayish material accumulating at the bottom of my pool, and it cannot be cleaned with my vacuum (when I try it just gets stirred up and floats in the water). What am I doing wrong??? HELP!!!!!!!!

[CrazyPoolMom]

Someone who knows more than me will be along, but I have figured out that if you are raising the PH, if you aerate the pool, like make a fountain, so that water is dropping back onto the surface, with the outflow from the pump, the TA will not rise up along with the PH. I just use a hose to do this, you have to get kind of creative.

So to lower your TA, you will have to keep droping and raising your PH while using aeration. It seems like it might be already dropping on you automatically.

It would probably help abunch if you would post all of your numbers. Those are probably going to be necessary to determine what the gray stuff is I would bet.

[vschuel]

Someone who knows more than me will be along, but I have figured out that if you are raising the PH, if you aerate the pool, like make a fountain, so that water is dropping back onto the surface, with the outflow from the pump, the TA will not rise up along with the PH. I just use a hose to do this, you have to get kind of creative.

So to lower your TA, you will have to keep droping and raising your PH while using aeration. It seems like it might be already dropping on you automatically.

It would probably help abunch if you would post all of your numbers. Those are probably going to be necessary to determine what the gray stuff is I would bet.

Well, I went to one of my local pool stores, and here is what they told me:

Free Chlorine: 5.0 ppm

TA: 140

pH: 7.0

TDS: 500 ppm

CYA: 50 ppm

He could not measure hardness due to lack of reagent at the store (???). Will the pH rise on its own by aeration WITHOUT adding soda ash, or will I still need to add it?

[CrazyPoolMom]

I think the PH will rise on it's own as long as you aerate.

[chem geek]

Trichlor pucks are very acidic so it will require you to add pH Up (same as Arm & Hammer Super Washing Soda -- pure Sodium Carbonate) periodically and this will raise both pH and TA, but at some point the TA will stabilize as outgassing of carbon dioxide will make the pH rise partially counteracting the drop from the Trichlor. This is all normal -- don't try and fight to keep the TA lower -- at some point you'll reach a balance.

HOWEVER, if you continue to use Trichlor then your CYA levels will increase unless you frequently backwash or have lots of rain and splash-out. You'll either have to use a weekly maintenance dose of PolyQuat 60 algaecide or will have to increase your FC level corresponding to your CYA level (keep the FC about 11.5% of the CYA level) or you'll have to manually dilute the water to keep the CYA stable. Or you could switch to a different source of chlorine such as bleach or chlorinating liquid, but you'll have to add these every day unless you have a pool cover. Or you could use Cal-Hypo, but that increases Calcium Hardness (CH).

[vschuel]

Trichlor pucks are very acidic so it will require you to add pH Up (same as Arm & Hammer Super Washing Soda -- pure Sodium Carbonate) periodically and this will raise both pH and TA, but at some point the TA will stabilize as outgassing of carbon dioxide will make the pH rise partially counteracting the drop from the Trichlor. This is all normal -- don't try and fight to keep the TA lower -- at some point you'll reach a balance.

HOWEVER, if you continue to use Trichlor then your CYA levels will increase unless you frequently backwash or have lots of rain and splash-out. You'll either have to use a weekly maintenance dose of PolyQuat 60 algaecide or will have to increase your FC level corresponding to your CYA level (keep the FC about 11.5% of the CYA level) or you'll have to manually dilute the water to keep the CYA stable. Or you could switch to a different source of chlorine such as bleach or chlorinating liquid, but you'll have to add these every day unless you have a pool cover. Or you could use Cal-Hypo, but that increases Calcium Hardness (CH).

But, will aerating the pool raise the pH level adequately? How long should I do so?