Trichlor+water exchange cost cheaper than bleach exclusively?

[AndyTN]

I'm posting this topic in the Agree to Disagree area because I know all the TFP veterans hate trichlor. I have followed the TFP process of liquid bleach but I can't turn completely away from the convenience of my trichlor feeder. This certainly would only apply to pool owners living somewhere with very cheap water for CYA purposes. I'm just doing the math to compare the cost per ppm of free chlorine using the trichlor pucks compared to liquid bleach at 10% and the cost per FC is about half the cost with trichlor. I'm using PoolMath to get my number below.

Cost of only FC: I can get a 40 lb bucket of trichlor from Costco for $70 and PoolMath says I can get 4.2 FC per lb so this comes to $0.42 per ppm of FC. Buying chlorinating liquid 10% from Home Depot comes to be $2.99 per gallon if I purchase 12 gallons at a time. PoolMath says I get 3.8 FC per gal which comes to be $0.79 per ppm FC, which is roughly double.

CYA math: PoolMath says 1 lb of trichlor yields 2.6 of CYA. I estimate I need 10-12 ppm FC of chlorine per week based on current usage of bleach so over 5 months time, this would mean I would increase my CYA by 150 for the season. Since water in Memphis is so cheap, it would cost be about $60-70 to drain half my water to cut CYA in half. Doing a half drain twice per year to control CYA would cost me about $130 for water.

End cost comparison: If I used exclusively bleach, this would add at least $100-150 of cost for inconvenience due to having to purchase quantities of 12 gallons at a time making multiple trips per season to HD, add bleach daily with specific measurements, and store 10-15 gallons of bleach in a air conditioned closet in my house with two young kids.

Anyway, if I use only trichlor, it will cost me approx. $100 + 130 (water) = $230 per season. Using exclusively bleach 10%, it will cost me approx $200 + 125 (inconvenience) = $325 per season. Taking out negative opinions about trichlor, does anyone see any holes in my math? I'm not saying I will abandon bleach for exclusively using trichlor and I still plan to use a combo of 2 gallons of bleach and 2-3 trichlor pucks per week. I'm just trying to do the math on the best combo strategy because I like the convenience of only having to add a gal of bleach twice per week without measuring vs. daily dosage and I don't like having 10-15 gallons of bleach on hand.

Feel free to pick this apart since I'm a pool novice but I'm an analytical person who likes to figure out strategies on my own.

 

[Donldson]

Trichlor is acidic, if your water is not basic or have a high TA you will need to include that in your numbers. You also lose a lot of dosing control. You are going to have to test your CYA weekly instead of monthly and increase your FC to keep in line with your ever-rising CYA. Also fill water in most places tends to be cold, can't speak for yours specifically but if I had to dump half of my warm pool water and refill with cold it would be a week or more before the pool use usable again. I don't understand how you can ignore all of this in your "inconvenience charge" that you appeared to add to the liquid chlorine cost estimate. Sounds more like you are just making up numbers to make them fit the way you want them to. Hardly scientific. Why do you think you need to store the chlorine indoors, anyway? A couple weeks in a shaded hot place is not going to destroy the chlorine.

Switching to saltwater would be cheaper in the long run and easier than either method. There is an upfront cost but it pays for itself over a couple of seasons.

EDIT: I missed pointing out that either plan works, it's not like you can't use trichlor with water exchange. Plenty of people in Florida do it because of all the rainfall it makes more sense since there is forced water exchange and they lost too much CYA with liquid chlorine. However, attempting to make it look more cost effective through adding subjective cost of "inconvenience" is not sound. You can manage your pool however you feel makes most sense to you, you don't need to convince us that it is cost effective by making up numbers. Attempting to extrapolate the costs of TFPC when you have only been doing it for a couple months isn't going to yield very reliable information.

 

[JoyfulNoise]

The notion that TFP “hates” trichlor is false. Trichlor is simply another form of chlorine with specific caveats about its use - it adds stabilizer to the water and it’s acidic. What TFP objects to is the overall poorly educated people in the industry that tell pool owners that they can keep dumping chemicals like trichlor and dichlor in their pool all season long without consequence.

There’s a difference there and it’s called “education”. TFP’s purpose is to “educate” pool owners about what pool chemicals are, what they do and how best to use them. It’s up to the individual pool owner to be responsible for their correct use.

Based on your post I see nothing wrong with your math other than a “convenience” charge that is subjective. You may find jug dumping to be a hassle but there are just as many people for whom adding bleach every day is no big deal. You could automate your bleach injection using a Stenner pump but you’d have to be careful not to have the puck feeder going at the same time. Conversion to an SWG is another option that makes chlorine additions hassle-free.

If you do a general analysis of chlorine products and you base the analysis on % available chlorine, what you find is that the solid chlorinating products (cal hypo, trichlor, dichlor) are a bit cheaper than chlorinating liquid (hypochlorite). So it’s up to you to use chlorinating products that give you the right mix of cost & convenience without adding a lot of additional chemical/maintenance burden. Water exchange is cheap where you live as contrasted to where I live with water that costs more then most of the rest of the country.

 

[Oly]

I applaud your analytic questioning, so lets have a closer look.
Do factor in your fill water chemistry in regards to TA and Ca and possible additions to keep your CSI in the zone.
Also the impact of draining may include permits, pump/hose rental etc.
Your time is involved with a drain and fill also.
I'm sure there are other considerations.

 

[Rancho Cost-a-Lotta]

There’s a difference there and it’s called “education”. TFP’s purpose is to “educate” pool owners about what pool chemicals are, what they do and how best to use them. It’s up to the individual pool owner to be responsible for their correct use.

Well said!

 

[Flying Tivo]

1.7ppm per day is not the norm, increase in summer and with usage. All the numbers will be higher.

 

[ajw22]

I believe that 40 lb bucket of trichlor from Costco for $70 is Clorox “blue “ that likely contains copper. You really don’t want to be adding copper to your water.

 

[JoyfulNoise]

You should also consider cal-hypo. When you compare cal-hypo to bleach on a % av. Cl2 basis, cal-hypo typically costs less. Then you can consider the convenience of throwing in a few scoops of powder as opposed to lugging a 9lbs bottle of bleach around. If you manage your pH and TA correctly, the cal-hypo can be a very good source of chlorine. I imagine in TN, with ample rainfall, your water is fairly soft and easy to maintain in terms of CH. High CH is by far much easier to manage than high CYA because CH doesn’t change your sanitizer requirements nor make chlorine less effective.

Look up WaterGuru, you might find it to be an interesting product for your pool ...

 

[AndyTN]

Again, my plan is not to use trichlor exclusively but to use half and half with bleach twice per week. I'm a newbie and learning a lot from this site so I'm not trying to question everyone's experience but just trying to get all that knowledge to shoot holes in my inexperience.

Trichlor is acidic, if your water is not basic or have a high TA you will need to include that in your numbers. You also lose a lot of dosing control. You are going to have to test your CYA weekly instead of monthly and increase your FC to keep in line with your ever-rising CYA. Also fill water in most places tends to be cold, can't speak for yours specifically but if I had to dump half of my warm pool water and refill with cold it would be a week or more before the pool use usable again.

Agreed about the increased usage of TA which wasn't factored and I agree with the extra step of testing CYA would factor into my "inconvenience" cost there too. Keeping a pool warm in Memphis is not a problem. By June, you are looking at ways to cool off your pool like with a fountain so using "less hot" tap water to refill would actually be a benefit to bring down the temp by 5 degrees.

The notion that TFP “hates” trichlor is false. Trichlor is simply another form of chlorine with specific caveats about its use - it adds stabilizer to the water and it’s acidic. What TFP objects to is the overall poorly educated people in the industry that tell pool owners that they can keep dumping chemicals like trichlor and dichlor in their pool all season long without consequence.

Sorry, I couldn't think of better wording but stated this because I see so many negative comments about trichlor on the site and responses of how I'm "doing it the pool store way" every time I mention trichlor. This leads newbies like me to get the impression it is evil for pools. I knew what I was proposing would get a lot of criticism which is why I posted in this area and I will learn more info from the criticism.

Do factor in your fill water chemistry in regards to TA and Ca and possible additions to keep your CSI in the zone.
Also the impact of draining may include permits, pump/hose rental etc.

CA won't matter because I have a vinyl pool. My drain to the pool connects right to the sewer with my pump on waste so no extra eqipment.

 

[AndyTN]

I believe that 40 lb bucket of trichlor from Costco for $70 is Clorox “blue “ that likely contains copper. You really don’t want to be adding copper to your water.

You are correct that it is the Clorox brand and has the "blue" stuff. I had a lot of copper staining issues on my old liner due to all the oak tree around my pool and the previous owners leaving a mountain of leaves in the pool when they moved out. I use the Natural Chemistry Metal Free and C-ulator packs (not sure if these are TFP approved) all season to proactively defend from the oak trees while testing for copper in the water. I would think with the metal sequestrant, packs, and with the partial drain, I would be keeping any copper from the Clorox under control. Thoughts on copper?

 

[Donldson]

Staining from organic matter is not copper related. Unless your fill water has copper or you are using copper algaecides you can discontinue your sequesterant and Cu-lator.

 

[Poolzzz]

Does your math include the ever increasing amount of chlorine needed to prevent algae when using trichlor?

How are you accounting for the cost and inconvenience of dealing with an algae outbreak when your cya is 150 etc?

You might be overestimating the hassle of adding bleach since you seem to be planning to measure daily? Most people just add a set amount once they learn their pool. Measure much less often. You might want to get a routine going first so you have some experience to really gauge if you need to find an alternative.

Are you trying to find the cheapest cost or the least hassle? Your title is cost but your post seems more concerned about "cconvenience". A mix of trichlor and liquid chlorine doesn't sound particularly hassle free for all the reasons people have stated. For convenience most people go to a swg.

 

[Flying Tivo]

Copper is a No-No in any type of pool.

 

[AndyTN]

Staining from organic matter is not copper related. Unless your fill water has copper or you are using copper algaecides you can discontinue your sequesterant and Cu-lator.

I will admit, the concept of copper staining due to the oak trees did come from the manager at Leslie's when I first started working on my pool. I know we are getting off topic from my original post but would excessive leaves from oak trees cause this type of staining? When we signed the contract on our house, the pool looked like the first picture with the pool perfectly stain free. After 45 days of them not cleaning out any leaves, the pool looked like the 2nd picture as soon as we moved into the house. The stains were removed (temporarily) with ascorbic acid and tests all pointed to a lot of copper in the water. I don't know how so much copper could get into the pool in 45 days when they were barely putting in any chemicals and the deep end had a mountain of leaves in it. I never got rid of the stains completely until I had a new liner put in and my Polaris is still stained from it.

 

[santacruzpool]

I think you should look again at the Joyfulnoise post above about using Cal-Hypo instead - as Matt mentions it might eventually require some sort of drain/refill, if the CH gets out of hand, but you would be much more stable long term with no CYA increases and no need to keep upping your FC amounts as the CYA goes up...and you might need to drain/refill much less often meaning less hassle...

 

[JoyfulNoise]

Oak tree leaves leave brown stains from tannins. Elevated chlorine levels will slowly oxidize and remove tannin stains.

If ascorbic acid removes the brown stains then it is almost always from iron (which would not be at all unusual for water in Tennessee).

Copper leaves brown stains that don’t lift with ascorbic acid but typically get darker. Copper is not usually found in terrestrial water sources but typically comes from the use of metal based algaecides and “multi-purpose” chlorinating tablets.

 

[needsajet]

You can get cal-hypo pucks nowadays as well, but be ever so careful not to mix them with trichlor pucks in a feeder, because the two together cause nasty gases and potential explosions. The cost may not work, I don't know, but the cal-hypo pucks are pretty handy. They dissolve more quickly than trichlor pucks, which may be a downside.

I agree it's a fallacy that TFP is anti-trichlor. TFP is just anti-poor-testing-and-lack-of-knowledge-about-pool-chemicals. I'm not sensing that from the original poster. I think they're smart to put the plan out there for feedback! In any event, if using trichlor pucks, be sure they are just trichlor without the extra "features"!

 

[JoyfulNoise]

Cal-hypo pucks, if you can find them, need their own special puck grinder/feeder. You can’t put them in a trichlor feeder. The older style cal-hypo pucks were made with a binder that would form a gooey, glue-like by-product.

 

[needsajet]

Our cal-hypo pucks down here look and act exactly like trichlor (except dissolve in three days in a floater rather than a week or two). I personally think it makes them dangerous, hence the warning!

 

[JoyfulNoise]

Our cal-hypo pucks down here look and act exactly like trichlor (except dissolve in three days in a floater rather than a week or two). I personally think it makes them dangerous, hence the warning!

Must be related to the opposite direction of Coriolis forces and the weird way toilets flush down under ... ?