Aquapure dead, numbers slightly off and what stabilizer?

[chris_r11]

Thanks for the suggestions.

I actually got away from leslies for not too much with the coupon they sent out and I bought some stabilizer at home depot. - $17 for 5#. Leslies was 20 for 4#. The also had a bag of shock for $4, so, hopefully I am back on track.

The one thing I learned (that will stick with me) is that since I have an infloor system, my skimmer does not go to my filter so all the CYA I put in just blew back into the pool. The infloor blew it around and disolved it pretty quickly (and I brushed it around as well so it would not bleach the plaster).

Wondering if you can explain to me why adding acid at 7.6 will use less. I am just trying to understand that. I know my habits are not the best. I sort of have it down to adding a half gallon once per week. Lazyness set it, I guess.

Again, thanks for all the advice.

Chris

[waterbear]

The one thing I learned (that will stick with me) is that since I have an infloor system, my skimmer does not go to my filter so all the CYA I put in just blew back into the pool. The infloor blew it around and disolved it pretty quickly (and I brushed it around as well so it would not bleach the plaster).

CYA will not bleach plaster.

Wondering if you can explain to me why adding acid at 7.6 will use less. I am just trying to understand that.

Chris

If you keep your TA on the low end, which yours is at 70 ppm (and is probably ideal for a SWG system) then by keeping the pH at 7.6 and not lower will result in less outgassing of carbon dioxide. It's the outgassing of CO2 that causes pH rise in a salt system (or any pool, for that matter). This is why we can raise pH by just aeration of the water and is why we use aeration as part of the process in lowering TA. If you have less outgassing of CO2 you will have less of a pH rise or a slower pH rise and therefore need less or less freqent acid additions to maintain the pH at 7.6. I won't go into the actual chemistry here but if you are interested check out this thread.
I have found that adding acid when the pH hits 7.8 and then lowering it to 7.6 is a workable plan. Adding borates to the water in a 30-50 ppm concentration can further help stabilize pH and lower acid consumption with a SWG.

[chris_r11]

Evan,

Thanks for the advice. One more question though. I thought I did not want to put borates into my pool if I was using chlorine. Am I confusing that with something else?

I do get tired of adding acid all the time to the pool so anything I can do to keep it down would be great.

Chris

[chris_r11]

Oh yeah, I know I have a high calcium hardness, but the person that changed the board in the aquapure said he took a look at the cell and it actually did not have much scaling, but it is something that I will keep an eye on.

Chris

[waterbear]

One more question though. I thought I did not want to put borates into my pool if I was using chlorine. Am I confusing that with something else?


Chris

Yes, you are probably confusing borates with either bromine or biguanide, bromine will convert a chlorine pool into a bromine pool and biguanide is NOT compatible with either chlorine or bromine. Borates are an excellent addition, IMHO. You can spend the money on a commercial borate product such as Proteam Supreme or Bioguard Optimizer or you can use 20 mule team borax. Check out this thread and this thread.

[chris_r11]

OK, well that brings up another question

So, if I have an 18k gallon pool, I would need about 18 boxes of 20 mule team and about 5 gallons of acid? I know not to put them in at the same time, but just trying to figure out the numbers.

Do borates disappear from the water?

is the 20 mule team the best way to put them in?

Since I can't do it with my skimmer, should I put them in a mesh bag and put that in the skimmer?

Thanks,

Chris

[waterbear]

60 oz 20 mule team (sodium tetraborate decahydrate) will raise 1000 gallons to 50 ppm borates so for an 18K pool you will need 1080 oz. Since each box contains 76 oz this is 14 boxes (14.2 boxes to be more exact but its a pool, not rocket science. 14 boxes is fine!)

You will need between 4 to 4 1/2 gallons of muriatic acid to neutralize the pH rise from the borax.

To dose your pool add 2 gallons of acid and 7 boxes of borax driectly to the pool and brush well to mix. Add 2 more gallons of acid and the rest of the borax and brush. Wait 489 hours and then readjust the pH down to 7.6 if it is higher than that. It will probably take between a pint to a half gallon more of acid to achieve this if you pH is high at this point. For your size pool I would add a quart of acid at a time, wait about 30 minutes, test the pH and repeat this until the pH hits 7.6 or goes a bit below it, whichever comes first. (if it goes below to around 7.4 don't worry, it will rise again)

Borates are lost by spashout, backwashing etc. the same as salt or CYA. They are easily tested with the Lamotte or AquaChek borate test strips (the Lamotte are a bit easier to read)

If you want to spend the money there is an eaiser way. You can buy Proteam Supreme Plus (a mixture of sodium tetraborate pentahydrate and boric acid) which is pH neutral. You would just add 60 lbs of it to the pool to achive the 50 ppm borates and will not have to worry about neutralizing the pH with acid. You should still check the pH after 48 hours and lower it to 7.6 if it is higher than that.

Downside is that this way is CONSIDERABLY more expensive (Where I work we sell the 10 lb Supreme Plus for $40! The larger sizes are a bit less per pound but still pricy compared to 20 mule team and muriatic acid!)

Whichever method you pick you should check your borate levels montly (just like your salt, CYA and Calcium) and when they drop to about 30 ppm bump them up to 50 ppm again.