cost

[sunofthebeach]

lets say I get 6% bleach at $2.50 for the 182oz bottle
I can get a 40lb bucket of tri-chlor whatever is is at Costco for $90 (85% cl)
I can get a 25lb tub of Cal hypo for $75 (60%cl)

Given these prices can someone tel me the which is the lower cost and by how much?
Can you give the answer in a price per 1 or 10 ppm of Chlorine in my 20,000 gal pool?

A 40lb bucket of tri-chlor will raise my Cya how much?
A 25lb tub will raise my CA by how much?

Thanks

[Yeggim]

Here's what I come up with using the "pool calculator" amounts to raise this size pool 1ppm.

Legal disclaimer:
I used to be good at math


tri=41 cents
bleach=56 cents
calhypo=77 cents

[waterbear]

However, there are hidden costs too
for every 10 ppm FC added by trichlor you are also adding 6 ppm CYA so in a short time your stabilzier level is too hgh and you need to either add algaecide to prevent algae (works for a while) or do partial drain and refill to bring the CYA back down. Also, trichlor is very acidic so you will be needing to raise both pH and TA on a regular basis.

Cal Hypo adds 7 ppm calcium hardness for every 10 ppm FC added so you calcium will continue to rise. Whether this is a problem depends a lot on your fill water, how well you monitor and maintain your pH, and how stable your water temperature is. It is essentially pH neutral on use since it goes in alkaline but the reaction of chlorine as it sanitizes is acidic so your main pH adjustment will be a bit of acid from pH rise caused by outgassing of CO2. this can be minimized by adjusting TA downward.

Bleach really only adds salt to the water which has no negative effects. (If salt was a problem then salt water chlorine generators would not work.)
It is also pH neutal on use like cal hypo. If liquid chorine in refillable carboys is available in your area at the pool stores then it is often a better value than buying laundry bleach so check the prices. The pool chlorine is approx. twice as strong as the (6%) bleach so you need about half the amount for the same FC level. Iif it works out to be less than half the price per oz (or gallon) then it is a better buy. However, you often have to buy the carboys outright. Generally they are in the neighborhoold of $5 for the 2.5 gallon ones. After the initial purchase you then just pay for the chlorine (and no plastic jugs to recycle). If pool chlorine is not available in your area in the carboys then bleach is usually a better deal then the gallon jugs of 10% liquid pool shock.

[Dubosity]

This is great info! And I love the new Pool Calculator (it may not be "new"...but I haven't seen it before).
Given that my local pool store does not charge for the jug, I've done the math and it is DEFINITELY cheaper than the bleach...cuts the cost by more than half! I'm concerned about shelf-life though. I don't know how long a jug will hold its strength, but if I buy enough for 1 week (which, I'm calculating to be about 2 jug's worth) then I can just make a weekly trip to the pool store. My questions are:

1) How long will a jug hold its strength (if kept in a cool, dark place)?
2) If I'm unable to get to the pool store, is it okay for me to supplement with the household bleach - ie, will there be any weird reactions if I add bleach after I've been using the pool-store chlorine? (I'm thinking the answer to this is no, given that they are both sodium hypochlorite and the pool-store one is just stronger...but I just want to confirm.)

It will also be great not to have all the plastic bleach bottles in my recycle bin every week!

[madwil]

the jugs are not likely to lose much weekly, when kept cool/dark/sealed (cap tightened)
You're pool doesn't know the difference between LC and bleach once it is in the pool- don't mix chemicals direct (this isn't a problem with bleach/LC, but good practice!) but add to pool will be fine without reactions...
I bypass the weekly recycle- got a small trailer that the bottles go in, carry to center at end of summer- 1 trip! Of course, I got the space to do that...

[Dubosity]

cool. Thanks!

[Yeggim]

Wow. That's less than .7 cents an ounce of household bleach. If you can beat $2.50 a gallon of Walmart bleach by half, that's $8.80 for a 5 Gal carboy of 12.5%. I'm paying $16.95 a carboy.

[sunofthebeach]

I would gladly pay more for the convenience of not dealing with 7 empty plastic jugs of bleach and making two trips to Walmart everyweek.

Yeggim,
Thanks for the info. My CYA is low so I will be switching to Trichlor for a couple of months.

[Yeggim]

I would gladly pay more for the convenience of not dealing with 7 empty plastic jugs of bleach and making two trips to Walmart everyweek.

Yeggim,
Thanks for the info. My CYA is low so I will be switching to Trichlor for a couple of months.

Keep track of that Trichlor. It has a 10 to 6 ratio of Chlorine to CYA. Every 3 lbs of Trichlor will raise CYA by 10 in a 20,0000 gal pool. A 40 pound bucket will put about 130 CYA in the pool.

[PoolParadise]

Someone help!

What is a carboy?