Why are pucks not cheaper?

[ericjdaniels]

(Just for background)

I am the guy who services our pool and my wife handles the chemicals. This year we have opened the pool for the first time, busted a hole in the pool, reinstalled the liner and refilled the pool, had a leak in the skimmer, fixed the leak, and now have a leak in our pump. Needless to say, we have done through quite a bit of water and we are still leaking it slowly. Thus, we've used up almost all of our CYA tests and have had to add a ton of chlorine over this season.

Now to the question:

My wife has decided she just can't justify the expense of doing the liquid bleach method suggested here. We have both tried to make it work but she says it can't be as cost effective as throwing in a puck every 3 days like our neighbors.

Sell me on why she is wrong. (Though any husband will know this is a dangerous question)

 

[Smykowski]

If you simply throw a puck in every three days, you will constantly add CYA to the pool. This will require additional chemicals to keep pH and TA from getting too low. Not to mention the sky high CYA you will have at the middle of the summer, which may lead to algae requiring more bleach to get through the SLAM process.

I have a 23K gallon pool and I spent a grand total of $100 on chemicals for my 4 month swim season this summer. BBB is cheap because you only put into the pool exactly what it needs, and you don't pay overpriced pool store prices.

Also, make sure you separate mechanical/equipment costs from chemical costs. Your problems above sound like they would have happened no matter whose advice you followed.

 

[duraleigh]

TFP doesn't really try to "sell" anybody anything. If your wife is convinced she should buy pucks and put them in your pool, that is her method that makes sense to her.

You might spend some time reading up in Pool School to find the pucks have some side effects that can cause problems and bleach has none of those. Not our place to "sell" her though.

For what's it worth, most of us find bleach cheaper than pucks so you might recheck the math just to make sure.

 

[BoDarville]

I would suggest looking at the total cost. FC is consumed daily, but CYA accumulates. Pucks add CYA, so you will need to test CYA at least every other week. As CYA accumulates, you will need more FC to maintain proper sanitation. The pucks continue to add CYA, so you need more FC. This is like the dog chasing its tail. Eventually the CYA build up to impractical levels and the FC added by the pucks alone will not be sufficient. One day, likely when you have planned a big pool party, you will wake up to an algae bloom. Here is a thread that puts some numbers to this: Frustrated. Look for Richard320's post on Page 1 dated June 27, 2013.

Refer to the Chlorine CYA Chart for more information on the chlorine/CYA relationship.

With bleach, you are adding FC without adding CYA. Since your CYA would stay relatively stable, you would only need to test your CYA about every other month or so. In addition, your target FC stays consistent. Plus, bleach is pH neutral whereas pucks tend to lower pH which would require you to take measures to increase it periodically to stay within the recommended pH range.

 

[ericjdaniels]

Great responses, keep them coming. And just to clarify, I/we don't feel like TFP is pushing us to anything...unless one defines that as suggesting what you believe makes sense.

We are just tight on money and on the outside it seems cheaper between chemical costs and test supplies, but that is why I am hoping to hear from those who use this method and can speak to why it is better AND cheaper. This is great stuff.

 

[woodyp]

Having to drain water and refill when your CYA level gets too high so you can actually KILL any algae has a cost all its own.

 

[Bama Rambler]

I think the number of issues you've had this year has clouded her vision. I just hope that you switching to tablets doesn't do the same to your pool!

You can make tablets work if you are willing to keep raising the FC as the CYA goes up and drain when it gets too high. You'll also need to account for pH and TA adjustment because the tablets are acidic. Whichever way you go, good luck.

 

[CeeElGee]

I'll add my two cents worth, even if it's not warranted. I spent two seasons with an older Intex (blue liner, white frame) and the Krystal Clear SWG they sell. I had sooo many problems with it (I take my share of the blame), so when we planned on a new pool this year we began investigating sanitizing options in the offseason. We finally settled on chlorine after talking to a "pool-store expert" who was more than glad to sell us an off-line chlorinator that would hold the pucks and dispense chlorine with little effort. After I bought one on eBay to match the new Hayward pump & filter we'd already ordered, I found this website and began reading.

It was then I realized how much of my problems were my simply allowing the automation of the SWG to replace good management. So after taking the plunge for a good test kit, I quietly (meaning, didn't tell my wife) didn't plumb the chlorinator when I plumbed the pump & filter and began doing the BBB thing. Although I did use dichlor granules initially to both sanitize my water and bring CYA levels up to where they belong, now all I do is a quick test every day or even every other day and add the necessary amount of bleach or liquid chlorine. I had a brief period when my pH started to creep too high due to my chronic elevated TA and I added some dry acid left over from the tons and tons I had to add last year. Problem solved. I'm very happy to stay connected to what's happening with my pool and add some liquid chlorine in order to have the pool water I always wanted from the SWG.

BTW, I found 12.5% liquid "shock" (actually just chlorine) at Menards this summer, four gallons for $9. I bought eight gallons and I'm still using it. Couldn't be happier Good luck.

 

[gtemkin]

I think it seems cheaper to pay once for a bucket of pucks, which seems to last forever, rather than shelling out weekly or bi-weekly for a gallon or two of bleach. But when you factor in the draining and refilling necessary to control CYA and all the other balancing activities associated with pucks, your better off with straight, simple bleach.

 

[Smykowski]

I think it seems cheaper to pay once for a bucket of pucks, which seems to last forever,......

And until you get to a forum like this and start really, really paying attention to your pool, no one actually keeps track of what they pay for chemicals in a season.

 

[chem geek]

Don't forget that Trichlor pucks are acidic, especially when accounting for chlorine usage/consumption, so you HAVE to add something to keep the pH from crashing so need to factor in the cost of pH Up in your calculation. Of course, you also need to do the calculation PER FC.

An inexpensive but good brand of Trichlor is GLB so let's look at the price of 3" tabs at poolgeek.com. The price ranges from $6.37 per pound if you buy only 4 pounds to $3.58 per pound if you buy 50 pounds. One pound of Trichlor in 10,000 gallons is 11.0 ppm FC so the price per FC is $0.58 to $0.33 depending on how much Trichlor you buy at once. That pound of Trichlor also uses up 7.7 ppm TA when the chlorine is used/consumed and it lowers the pH.

To restore the TA, 10.95 ounces weight of pH Up is needed, though that won't completely restore the pH unless there is carbon dioxide outgassing. The GLB pH Up ranges from $2.38 per pound if you buy only 2 pounds to $2.01 per pound if you buy 8 pounds. So per FC (so multiplying the per pound by 10.95/16 and dividing by 11.0) the price per FC is $0.15 to $0.13 depending on how much pH Up you buy at once. So the total per FC is $0.73 to $0.46 depending on quantities purchased.

Compare this to the price of chlorinating liquid or bleach. At Walmart, Clorox Concentrated Regular Bleach, 121 fl oz is $3.50. 121 fluid ounces of 8.25% bleach in 10,000 gallons is 8.2 ppm FC so the price per FC is $0.43. I buy 12.5% chlorinating liquid at $4 per gallon which is 12.5 ppm FC in 10,000 gallons so is $0.32. However, if you look at the thread Bleach Prices 2013 you will find that you can get bleach or chlorinating liquid for even lower prices. If your pH rises when using bleach or chlorinating liquid, then you may need to add Muriatic Acid so would factor in that cost. At Orchard Supply Hardware, Kem-Tek Muriatic Acid (half-strength, 14.5%) is $10.99 for 2 gallons so adding 2 cups per week in 10,000 gallons and presuming 14 ppm FC over the week, this comes to $0.05 per FC that might be needed though lowering the TA in the pool can usually minimize this need.

Of course, one could also probably find lower prices for Trichlor as well and one could use Arm & Hammer Super Washing Soda instead of pH Up. At Walmart, Arm & Hammer Super Washing Soda is $0.94 per pound so about half the price of pH Up product. So that would lower the total Trichlor + pH Up equivalent per FC to $0.64 to $0.39.

It is not always the case that bleach or chlorinating liquid will be less expensive than Trichlor, especially if you use Super Washing Soda instead of pH Up, but Trichlor use is never that much less expensive. And as others have noted, for every 10 ppm Free Chlorine (FC) added by Trichlor, it also increases Cyanuric Acid (CYA) by 6 ppm and the buildup of CYA can cause problems requiring extra cost to fix or prevent.

Why in the world is your wife thinking that using bleach is more expensive than using Trichlor? Did she look at receipts of how much was spent when using Trichlor vs. what was spent using bleach?

 

[CUTiger78]

Why in the world is your wife thinking that using bleach is more expensive than using Trichlor? Did she look at receipts of how much was spent when using Trichlor vs. what was spent using bleach?

What was she thinking? "Gee whiz, more money on bleach everytime I go to the grocery store. And you're making trips to HD or Walmart to buy even more! This bleach cost is out of control. Let's go back to ordering pucks. Next day delivery is free & it's gotta to be cheaper!"

It's a visibility thing. She sees that they're spending $$ on bleach regularly. And, maybe it leaks on the carpet in the car & bleaches a spot. Then, there's all those empty bottles to throw away or recycle. With the 50lb bucket of pucks, there's a 1-time online purchase (maybe 2 per season), it's easy to forget about, and she might not even notice the charge when the credit card bill comes in.

I can see it happening. I've probably done it myself. Ya know, it's not that easy to do the number crunching and financial analysis Chem Geek did!

I'm just speculating here and I think someone mentioned a similar thought earlier.

 

[ericjdaniels]

CUTiger78 is right on. While I want the "other perspective", that is exactly what my wife has probably been feeling. One ruined shirt is enough to consider the alternative.

Nonetheless, I am VERY thankful for the numbers by Chem Geek. Now to have my wife read the thread and see what she thinks.

(A former molecular biologist on her way to being an actuary can handle all this math. I'm gonna go watch heck on Wheels)

 

[ericjdaniels]

Hi all! Thanks so much for the advice. Sorry but I didn't fully talk with Eric before he posted our questions on this board. I totally agree that if our CYA would stay stable then using the liquid chlorine would be a no-brainer.

Unfortunately, our CYA levels drop very quickly. And our test kit seems to have only come with the ability to test for it about 7 times. I know from Pool School that you need a higher FC the higher your CYA is. Since I don't have any reasonable way to know our fluctuating CYA level, I don't know what the FC should be. That is why I was thinking that I would use something that would add chlorine and CYA (since both seem to go away quickly for us.) Any suggestions for this since the pucks seem to not be a good idea?

Or is there nothing to be done until the leaks in the pump have been resolved? We can just cover it up and call it a summer and start over next summer after we have had time to fix the leaks.

Thanks again for all your time!

 

[Smykowski]

Unfortunately, our CYA levels drop very quickly.

This is very unusual, and needs to be addressed.

To be clear, we are not anti-puck. We're just anti-puck if you're A)using them exclusively or B)blindly throwing them in the pool and hoping for the best. Your understanding is above and beyond the average "puck user." In your case, you may be ok, but it's obviously because you have an underlying issue that needs to be fixed.

 

[linen]

I agree with smy, that is unusual. Do you know why?

On the cost of pucks vs. bleach, pucks are not cheaper for me...the very best price I can get 3" trichlor pucks for locally ~$1.50/each. The equivalent amount of 12.5% liquid chlorine is 57 oz. I get a gallon of the 12.5% for $2.50, so my cost per 57 ounces is $1.11. So the liquid chlorine is cheaper for me and that is before considering all the other chemicals needed with the pucks to keep the pool balanced plus the cost of draining/refilling when the cya gets too high.

 

[Donldson]

This is being pretty well discussed, but there is something that jumped out at me I wanted to talk about:

...but she says it can't be as cost effective as throwing in a puck every 3 days like our neighbors.

If you just throw a puck in every 3 days it is probably cheaper, but that is comparing two very different things. To properly chlorinate a pool you would need to test and make sure that the FC level is staying in line with the CYA level. Just throwing a puck in is not doing that. So while it may cost more than that to properly chlorinate with bleach, it would also take more than 1 tablet every 3 days to properly chlorinate. Following the chart will assure proper sanitation of water, that all nasties are destroyed and algae is kept at bay. The other way is rolling the dice.

As has been said, you can properly chlorinate with trichlor. You just need to carefully watch the pH, TA, and CYA levels and adjust as needed. It is up to each person to decide how to chlorinate, but the FC/CYA chart really needs to be followed.

 

[ericjdaniels]

I think that we are losing so much CYA because we are losing a significant amount of water from a leaky pump hose. Eric plans to fix that once we close up the pool for the summer. But because of that steady water loss, I can't keep an accurate read on what our CYA level is. That was why I was considering using a puck that would add chlorine and CYA.

But all of your advice makes me hesitant to do that. So unless there is a nice way to keep a pool chlorinated while not really knowing the CYA, I think that we may just need to call it a season and fix our leaks to stop the water loss.

Thanks again SO SO much for all of your help and advice and we are looking forward to hopefully having a trouble free pool next year!

 

[GreatCanadian]

My chemical costs for 3 months so far:
3 boxes of baking soda @ $1.39 each
Stabilizer (CYA) $20.31
I have a SWG on its third season that I paid $150 for-so $50 per season so far

I did add borates but that's optional. My ph locks in at 7.5 so I don't need muriatic acid except to adjust pH after adding borates. (borates probably assisting pH stability.

So outside adding the optional borates its pretty cheap. I have friends spending more than that on EACH trip to the pool store. They're puck users with nonending issues because they do not understand the chlorine/CYA relationship.

 

[duraleigh]

But because of that steady water loss, I can't keep an accurate read on what our CYA level is.

Yeah, that sounds like you have a pretty significant leak that needs repair first. That's the same course of action I would take. Next year, your CYA will remain stable (and your other parameters as well) and you'll have a much easier time with your pool.