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Are All Chemicals Equal?


BrianN

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Just wondering if PH+ and PH- are the same for pools as they are for hot tubs?

Reason I ask is, I am having problems getting the TA and PH levels where they need to be. I went and had my water tested on Friday. Spent all weekend adding the chemicals they said to add and the time intervals they suggested. My water is still a bubbly white. I went in for another water test today, and, it seems that the levels are even worse than when I started on Friday.

I was thinking it may have some thing to do with the PH+ and PH- chemical I am using. I bought it at the local hardware store, and, it says for use in pools.

Is it okay to use this in my Hot Tub?

Thanks in advance.

Brian

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Yes, in general the chemicals are identical. Most pH Up products are sodium carbonate and they raise both pH and TA. Some pH Up spa products are sodium bicarbonate which is also in other Alkalinity Up products for both pools and spas. This raises the TA much more than the pH, but nevertheless is in a few spa products labeled pH Up.

pH Down is usually sodium bisulfate for both spas and pools. One can also lower pH using Muriatic Acid though that is more commonly used for pools than for spas

If your water gets cloudy when adding pH Up, then your water may be saturated with calcium carbonate. If you have high TA and/or CH then that is probably the cause. It sounds like your pool store is having you yo-yo trying to get the TA lowered by adding acid (pH Down) but then they stupidly have you add pH Up to raise the pH. This has the opposite effect of what you want and actually increases the TA level.

Why don't you take charge of your spa by getting a proper test kit -- the Taylor K-2006 you can get at Amazon. Then post your full set of water chemistry numbers and we can go from there. If your TA is above 80 ppm, then lower it by following the procedure in the thread Lowering Total Alkalinity. Notice that to lower TA you do NOT add pH Up or any other pH raising product. You only add acid and aerate the water because that is what drives out carbon dioxide from the water -- TA is mostly a measure of the over-carbonation of the water.

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My TA is way above 80ppm. That is since I did the guidelines set out by the pool store on my last visit.

I always wondered why they were getting me to use PH- to lower TA, and then PH+ to raise the PH. I figure now that it is just a money grab for them. I live in a small town, they are the only pool store within 100kms. So, the more chemicals I need, the more I will need to buy from them.

Anyways, I will look into the test kit and let you know the results.

Thanks for the info.

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It is insane to have people use pH- and then pH+ since the net result is pretty much the same as adding alkalinity up (baking soda) plus salt (sodium sulfate in your case).

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These are the numbers and instructions they gave me yesterday to get my tub back to "normal".

Seems like a lot of chemicals, and, takes A LOT of time, and many, many cycles.

Volume: 1363Litres

System: Mini Pucks

Temperature: 40.0

Solids: 0

Free Chlorine: 0.0

Combined Chlorine: 0.0

pH: 8.0

Alkalinity: 230

Calcium: 0

Iron: 0.0

Copper: 0.0

Clarity: Clear

Algae: None

Balancing Procedure - Mini Pucks

The steps below should be followed in the order presented.

Step 1. Your Total Alkalinity is HIGH. To lower alkalinity, you can dilute the hot tub using water that has a lower alkalinity

level or add 420 grams ( 1 cup + 3 tablespoons + 2 1/2 teaspoons) of PH MINUS. Add 22 gr (1 tablespoon) of

PH MINUS at a time, circulating 20 minutes between additions. Check the pH level after each addition. If the pH

level falls to 6.5 then stop and wait until pH level comes back up then resume procedure until all of recommended

amount has been added. Readjust the pH level to 7.2. Maintaining alkalinity levels between 100 and 120 will

prevent pH bounce, scaling of metal equipment parts and clogging of heater pipes.

Step 2. Your Calcium Hardness is LOW. Add 358 grams ( 1 1/3 cup + 2 tablespoons) of PROTECT to prevent

corrosion to metal equipment parts. Premix in a plastic bucket of hot tub water. Pour evenly around perimeter of

hot tub, with the circulation system running. Maintain calcium hardness between 150 and 200 ppm.

Wait for 15minutes before proceeding.

Step 3. No Adjustment of pH should be attempted until Total Alkalinity in previous step has been corrected. Retest pH

after completion of alkalinity adjustment. Adjust pH by adding PH MINUS or PH PLUS as indicated. Add no

more than 15g (1 tablespoon) at a time. Circulate and repeat every 20 minutes until recommended amount has

been added or test results stabilize between 7.2 and 7.8.

Step 4. Your present chlorine level is LOW. Add 16 grams ( 1 tablespoon + 3/4 teaspoon) of LlTHCHLOR to increase

chlorine residual. Remember to remove cover, and DO NOT use hot tub or replace cover if chlorine reading is

above 5 ppm. Maintain chlorine residual between 3 and 5 ppm.

Wait for 15minutes before proceeding.

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The good news is that their procedure for lowering the TA doesn't have you adding pH Up, but you are right that their procedure is too slow. You could add 200 grams of dry acid at first and just aerate the water to get the pH Up and then add 100 grams, wait until the pH goes up and then another 100 grams which should get you from an initial 230 ppm TA to just below 120 ppm TA. You could keep going down to around 80 ppm by adding another 100 grams of dry acid.

You don't need more than 120-150 ppm Calcium Hardness (CH) and that is to prevent foaming. Metal corrosion does not come from low calcium and your spa doesn't have plaster surfaces to protect.

And of course you need chlorine in your water.

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