Trichlor questions

dombey

Well-known member
Apr 25, 2010
74
Sunny Phoenix AZ
Hi guys,
So I've owned a pool for about 4 months now. When I bought the house the first thing I did was get on this site and start learning...it led me to drain the pool that has something like 300ppm of CYA due to long-term trichlor use. Since then, I've had a beautiful pool and nothing has gone in it but liquid chlorine and acid.

I'm starting to have second thoughts, however. The cost to drain my pool was about $200 for 28,000 gallons. In other words, the cost of water is miniscule compared to what I spend on chlorine and acid...right now I'm running about $150/month in chemicals...a gallon of 10% chlorine every other day and a gallon of acid every 5-7 days. I live in phoenix and the pool gets used a lot by the dog, leading to a lot of aeration and acid demand. My TA is around 60 and my CYA around 50 as well.

Use of trichlor would remove some of the daily maintenance, as well as help to keep the ph down.

I'm wondering if it isn't much more cost efficient, not to mention more convenient, to switch it back to trichlor and do the math to keep the CYA in check by backwashing enough each week to remove a week's worth of CYA.
Has anyone crunched the numbers to determine if this is possible and/or cost efficient? Might have to bring up the CYA to a higher number to make the math work...
 

Beez

LifeTime Supporter
May 19, 2009
785
Dallas, TX
:shock: WOW!!! :shock: $150/month? I'm glad I don't have swimming dogs!

Granted, my pool is smaller than yours, but my monthly chem bill at the peak of swimming season never exceeds $25. I wonder if you are truly getting 10% chlorine...have you tried bleach instead to see if you still have the same FC demand? You would probably benefit from a higher CYA as well, maybe around 80ppm.
 

svenpup

LifeTime Supporter
Nov 18, 2009
835
Sacramento, CA
Many people come to this site after major frustration and major $$$ spent following the pool store advice trying to clear pools with high CYA levels. You could do a quick search though recent posts and find people who were getting raked over the coals by their pool store.

By my calculation, assuming 3ppm FC loss per day you would be adding 13ppm CYA per week. This would translate to a ~20% drain every week or about 80% or 22,000 gallons every month. There's your $150 per month and you haven't paid for trichlor yet.
 

dombey

Well-known member
Apr 25, 2010
74
Sunny Phoenix AZ
Beez said:
:shock: WOW!!! :shock: $150/month? I'm glad I don't have swimming dogs!

Granted, my pool is smaller than yours, but my monthly chem bill at the peak of swimming season never exceeds $25. I wonder if you are truly getting 10% chlorine...have you tried bleach instead to see if you still have the same FC demand? You would probably benefit from a higher CYA as well, maybe around 80ppm.
I haven't tried bleach, but when I add a gallon of 10% chlorine I get a bump of about 3.5ppm - which is dead-on according to the pool calculator. So I assume it isn't an efficacy issue.
 

svenpup

LifeTime Supporter
Nov 18, 2009
835
Sacramento, CA
...and ditto to Beez and MiTS

I use:
  • 5 cups of 12.5% per day = 150 cups per month at $2.75 / gallon = $25
    2 cups of 31.45% MA every three days = 20 cups per month at $4.25 / gallon = $5

$30 per month
 

dombey

Well-known member
Apr 25, 2010
74
Sunny Phoenix AZ
Melt In The Sun said:
What are you paying for LQ and acid? That does seem really high.
I buy it for the convenience at Fry's...something in the vicinity of 7-8 bucks for 2 gallons of 10% Chlorine... and I believe 9-10 bucks for 14.5% acid. The price varies depending on sales, so the $150 is a guesstimate based on what I'm using and average prices...realistic range is about 120-160 bucks depending on sales, rain, pool use, etc.

I've done the math on the chlorine vs. walmart and it can be had for just a tad less at walmart but that is pretty much eaten up by the cost of gas in my wife's SUV driving to the nearest walmart and back. :)
 

dombey

Well-known member
Apr 25, 2010
74
Sunny Phoenix AZ
svenpup said:
...and ditto to Beez and MiTS

I use:
  • 5 cups of 12.5% per day = 150 cups per month at $2.75 / gallon = $25
    2 cups of 31.45% MA every three days = 20 cups per month at $4.25 / gallon = $5

$30 per month
dude where are you buying your stuff? that is substantial savings to what I'm paying, esp on the acid.
 

Melt In The Sun

TFP Expert
LifeTime Supporter
Oct 29, 2009
3,899
Tucson, AZ
Well, you should be able to cut your acid costs by 2/3 by buying 31.45% at Lowe's. Down here it Tucson it's $6, and will go twice as far as a bottle of 14.5%. Trichlor will almost always be much more expensive. Sounds like you need an SWG!
 

Beez

LifeTime Supporter
May 19, 2009
785
Dallas, TX
Also, just to reiterate, if your pool is in full sun all day with the sizzling heat in Phoenix you would almost certainly benefit from a higher CYA.
 

dombey

Well-known member
Apr 25, 2010
74
Sunny Phoenix AZ
Beez said:
Also, just to reiterate, if your pool is in full sun all day with the sizzling heat in Phoenix you would almost certainly benefit from a higher CYA.
Right. I wanted to leave myself some room on the CYA because I use trichlor tabs whenever I go on vacation - I might try uppping it a little though and see what the impact is.
 
G

Guest

The "problem" with the SWCG in AZ is the hard water. They tend to calcify pretty quickly. Not a real big deal if you keep a clean cell (do you know what your CH levels are?), but it is definitely not a "set it and forget it" alternative!