Pool Shock With Powder

by Jennifer

I have a 1500 gallon pool and I didn't see my kind of chlorine in your list.

So I was wondering how many ounces of the powder shock (brand kem-tek. active ingredient trichloro-s-triazinetrione). It comes in 10 oz bags of powder and my brother put in 5 oz.

So how many ounces am I really supposed to use and how long till I let my daughter play in it?

Thanks for the question Jennifer

Trichloro-s-triazinetrione is the active ingredient in Trich-chlor tablets. The question said your brother used 5 oz. of the powder shock for a 1500 gallon pool. This should be good. With powder, to shock per 1000 gallons, you'd use 2 - 2.5 oz. Your pool received 2Xs that amount, which is fine.

I'd suggest testing the chlorine and the stabilizer. You want the chlorine reading between 1.5 - 3.5ppm and the stabilizer 30 - 50ppm.

Swimming Pool Chlorine

Pool Shock

Pool Chlorine

For every 10ppm of chlorine added with Trichlor you'll raise the CYA by 6ppm.

By using what you did, you probably got some stabilizer in the pool as well. Unless it's between 30 - 50ppm, I'd suggest using either regular liquid chlorine or bleach for a sanitizer. If the stabilizer gets too high, above 80ppm, you'd need to do a partial drain and refill. There's no chemical to get it out of pool water.

If the stabilizer is low, under 30ppm, use it again until your reach the target of 30 - 50ppm, then switch to liquid chlorine or bleach for maintenance.

It's safe to swim in a pool with a chlorine level of 8ppm, but you'd probably want to wait until it get down to 5ppm. While using the pool combined with the sun and heat, the chlorine level will drop anyway.

Hope this helps and have a great Summer.


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White Cloudy Pool After Shocking

by Mary

I was told to put 8lb of shock to my pool. It turned cloudy and white for over a week now and the shock powder is on the bottom, floating in water.

How can I get it all to settle on bottom so I can see to vacuum?

My chemical readings are:

Chlorine 0
CC 0
pH 8.6
Hardness 95ppm
TA over 285ppm
CYA 3ppm
Copper & Iron 0


Thanks for the question Pat

An easy way to allow chemicals to settle to the bottom is to turn the filter off for 4 - 5 hours, then you can vacuum. However, this may not clear up of the cloudiness. The pool could be cloudy for a number of reasons:

Cloudy Pool Water

If you're shocking the pool because of an early algae bloom and are taking proactive measures, that's great. But, pools rarely need to be shocked for weekly maintenance if the chemicals are correct in the first place. A cloudy pool for a few hours after a shock with chlorine granules is normal, however, days or a week is not.

First, you need to reduce the TA. Normal range is 80 - 100ppm, 120ppm being the top. It's 0.8qrts. of acid per 10,000 gallons to lower the TA 10ppm. You have a 13,000 pool and the TA is 285ppm. You need to lower it to 100ppm. That's a drops of 185ppm, which is alot. You'll need patience with this. You're going to need about 6 gallons of acid to accomplish this.

With the pump off, add 2 gallons of acid in the deep end in one spot. First get a 5 gallon bucket and fill it 1/2 with pool water. Add the acid, stir with a stick, and slowly pour into the pool. Gently sweep the bottom to break up any hot spots of acid. Allow to sit for about 3 - 4 hours, turn the pump back on, and FILTER for 8 - 10 hours, then retest. Do this in the evening, then retest in the morning Be sure to sweep, but do this gently.

Pool Alkalinity

Total Alkalinity

The acid will have a slight effect on the pH as well so be sure you're testing that along with the TA. A high TA will chew up other chemicals pretty fast.

Next is the chlorine. Don't use calcium hypochlorite. That has a pH of 12 and will keep your pH high if you shock the pool. It's already 8.6 so you don't want it to go any higher. Your CYA (stabilizer) is low, 3ppm. The range is 30 - 50ppm. Sorry, but chlorine tabs won't raise it fast enough. You need to use Dichlor chlorine. Shock the pool with Dichlor chlorine. This is a stabilized form of chlorine. Once you reach the 30 - 35ppm mark, stop with Dichlor and go back to regular liquid chlorine.

Be careful when using Dichlor as it can get out of hand quickly. For every 10ppm of chlorine added with Dichlor, you'll raise the CYA by 9ppm. For every 10ppm of chlorine added with Trichlor tabs you'll raise the CYA by 6ppm.

You can shock the pool after you make the adjustment to the TA. This is what I mean... You allow the acid to sit for 3 - 4 hours, then turn the pump back on. At this time you can shock the pool with Dichlor. It's 1 1/3lbs. of Dichlor per 10,000 gallons to shock and pool and add 9ppm CYA.

You're going to need about 6 - 7 lbs. of Dichlor to pull this off. Shock using 2.5 - 3lbs. of Dichlor first, then retest after 8 - 10 hours of FILTERING.

You have a vinyl pool so the calcium is not that important. It's 95ppm right now which is fine. Calcium is mostly for plaster/concrete pools so there's no pitting. You also don't need another added expense.

The pH is high at 8.6. This is why you shouldn't use calcium hypo. I know this for a fact because when I shocked the Y pool with cal hypo the pH always went through the roof. If you have a problem with high pH, use liquid chlorine.

To reduce the pH you'll use muriatic acid. It's 12oz. of acid per 10,000 gallons to reduce the pH 0.2. Your pH is 8.6 and needs to get down to 7.6. That's a good size jump. Start with one qrt. of acid broadcast around the perimeter of the pool with the pump on FILTER. Retest after 8 - 10 hours and make another adjustment. Sweep very well after each application. Unlike when you make an adjustment to the TA, you can brush pretty hard and mix up the acid.

Swimming Pool pH Levels

Pool pH

Summary -

1. Add acid to reduce TA. After you turn the FILTER back on after 3 - 4 hours, shock with Dichlor and allow to FILTER for 8 - 10 hours. Retest TA, chlorine, and CYA. Make another adjustment if needed.

2. Get the pH to 7.6. If you overshoot a bit, say to 7.4 or 7.2, that's fine.

3. No calcium chloride. You don't need it. Your reading of 95ppm is fine for a vinyl pool.

4. No cal hypo or chlorine granules. Use liquid chlorine after you get the CYA to 30 - 35ppm. Use a tab floater. Never put tabs in the skimmer.

5. Get the pH down to 7.6 using acid

6. Because your chlorine is low right now, an algaecide would be good until the chlorine level stabilizes. Use a PolyQuat 60. Anything else is cheaper and has metal fillers in them. The algaecide is just to use temporarily until you get things under control. Normal pool maintenance shouldn't require anything extra.

You don't need any extra super shock or other stuff the pool store tries to sell. In effect, it's the same thing, just in a fancy package that they can markup 500%. A 16oz. box of baking soda is about $2.99. A 16 oz. bottle of pH Up is between $8.99 and $12.99. Both are sodium bicarb or sodium carbonate. Go figure.

Pool chlorine is sodium hypochlorite 16%. Clorox bleach is sodium hypochlorite 6%. Same stuff, only the strength is different.

If you would like personal assistance, I do phone consultations for a donation of your choice. It makes things go much faster. If you choose to not go that route, we can correspond by email.

Contact Me


Hope this helps and have a great Summer.


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Can You Use Pool Shock In Your Hot Tub?

by Jane
(Kitchener, Canada)

I have been using spa shock for my hot tub but it's very expensive.

Is the spa shock the same as the pool shock or should I use shock that is specifically designed for a hot tub.

Is there a difference?

Thanks for the question Jane

The short answer is yes, you can use pool chlorine to shock your hot tub.

I always advise people to not use anything that called "Super Blast-Out" Pool Shock or Mega this and that. It's all the same thing... chlorine.

You're only paying for the fancy package with fire and flames.

People are told and think that products such as those are totally different than regular chlorine and nothing could be further from the truth. It's either calcium hypochlorite 68% or sodium hypochorite 15%. You can use regular grocery store bleach. It's nothing more than watered down pool chlorine at 6% sodium hypo. Here are a couple of interesting links:

Clorox bleach

Click on the sodium hypo button

Pool chlorine

Section II Hazardous Materials box

If you have hard water, above 100 - 150ppm or so I'd tell you to use liquid chlorine. If it's softer, say below 50ppm, you can use granular chlorine but keep any eye on the hardness. 150 - 250ppm is the range you want to say in.

To post a reply, or if you have a similar question, you can see your post on the Q&A page in the "Hot Tub/Spa Questions" category.

Check back to this post for updates or answers.

If you need immediate assistance (within 24 hrs) or for emergency personal assistance, you can make a donation of your choice and I'll answer your questions by phone.

Contact Me


Hope this helps.


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