Baking Soda?

Causes and cures for cloudy swimming pool water. Milky pool water, white, pink, brown, purple, black cloudy water.

Baking Soda?

Postby Pool User » Sat 07 May, 2011 07:44

What does baking soda do for a pool? Mine is 15 x 30 and 4' deep. I see baking soda bags in the area of the pool chem supplies. I also have some balance pak 200 left over from my spa. Can it be used in the pool as an alternative of some sort?
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Baking Soda?

Postby chem geek » Sat 07 May, 2011 12:13

Baking Soda is sodium bicarbonate and is used to raise the Total Alkalinity (TA). It is in the BioGuard® Balance Pak® 100 though the ingredient is called by a synonym of sodium hydrogen carbonate.

BioGuard® Balance Pak® 200 is sodium carbonate and is used to raise the pH though it will raise the TA as well. If you want to raise the pH with half as much rise in TA, you can use 20 Mule Team Borax instead (you use about twice as much by weight for the same pH rise). You can use The Pool Calculator to calculate dosages.

In a spa, it is unusual to need to raise the pH since the aeration from jets along with a higher TA level is usually enough to keep the pH stable when using a net acidic source of chlorine such as Dichlor, but continued use of Dichlor will lower the TA over time. For every 10 ppm Free Chlorine (FC) added by Dichlor it not only increases Cyanuric Acid (CYA) by 9 ppm, but also lowers Total Alkalinity (TA) by 3.5 ppm.
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Baking Soda?

Postby Pool User » Mon 09 May, 2011 08:34

i have a 3" tablet in the skimmer basket and want to use a bag of super shock mixed with water to add to pool. I also have baking soda and a bucket of stabilizer. My questions are:
1. When i''ve mixed the super shock in a bucket of water, do i add all of it directly to pool or do i add some to skimmer basket and rest to where the water comes into the pool?

2. Can i add baking soda, super shock and stabilizer all at once, or do i add some items and wait before adding the others?
Hardness = 0

FC = 0

PH = 6.4 - 6.8

TA = 40

CYA = 0
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Baking Soda?

Postby chem geek » Mon 09 May, 2011 13:06

Sorry, I was thinking "spa" because of your leftover chemicals for the spa. Yes, Trichlor pucks/tabs are very acidic. For every 10 ppm Free Chlorine (FC) added by Trichlor, it also increases Cyanuric Acid (CYA) by 9 ppm and decreases Total Alkalinity (TA) by 7 ppm.

As for adding concentrated chemicals to the pool, it is best to add them slowly over a return flow in the deep end with the pump running. To ensure thorough mixing, lightly brush the side and bottom of the pool in the area where you added the chemical. Your circulation system should then distribute the chemical through the rest of the pool. There are some chemicals you do not want to put into the skimmer, such as Trichlor pucks/tabs (except for some special ones that don't dissolve when there is no water flow) so it's safest to add them over a return flow. For some chemicals like baking soda used to raise TA, it's fine to distribute it around the pool and most algaecides, enzymes, clarifiers, etc. say to distribute around the pool as well.

Wait in between your chemical additions and NEVER mix concentrated chemicals together. As for adding stabilizer, it dissolves slowly so you can put it in a sock and hang it over a return flow or you can add it slowly in the skimmer to get caught in the filter though the latter will take days to dissolve. I use an old T-shirt I put over my skimmer basket and add the CYA to it, but I also have floor drains and a skimmer bypass inlet so there is no risk of blocking the suction input to the pump.

For your pool using Trichlor, your TA level is way too low which is why your pH tends to drift too low. Though you can add baking soda, you can also add some pH Up (sodium carbonate; Arm & Hammer Super Washing Soda) to raise both pH and TA though you'll also need more baking soda since your TA is so low.

Since you have been using Trichlor pucks, I doubt that your CYA is really 0. However, you also show that FC is 0 so why is that? Did you just open the pool over the winter? If so, then if you closed with CYA being present then bacteria could have converted it to ammonia which can create a huge chlorine demand. I suggest you read the Pool School for more info on opening your pool and maintaining it. If you use only Trichlor puck/tabs, then the CYA level will rise and if you don't proportionately raise the FC level then algae can grow faster than chlorine can kill it unless you use supplemental algaecide or phosphate remover at extra cost. The alternative is to get the CYA to the right level initially and then use chlorinating liquid or bleach as your primary source of chlorine. The downside is that this usually requires manual chlorine addition every day or two unless you've got a mostly opaque pool cover.

Also, I doubt that your hardness is really 0. Are you using test strips? They are next to worthless. You should get yourself your own good test kit -- either the Taylor K-2006 or the TFTestkits TF-100.
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