Who's figures do I use?

[Blue114]

Hi
I'm currently getting my pool balanced after refilling 2/3 of the water. I have a SWG. The pool render people recommend these levels to inhibit calcium buildup on the walls.

TA 120 - 140
PH 7.4
CH 200
FC 2-3
CYA 30 - 40

TFP recommendations for SWG are

TA 60 - 80
PH 7.5 - 7.8
CH 250 - 350
FC 3 - 5
CYA 70 - 80

Do you think the TFP levels ( which I would prefer to use ) would have any more effect on the calcium being drawn from the walls and floor than the other levels?

My current levels are
TA 140
PH 7.4
CH 250
FC 3 ?
CYA 40

These are only approx cause I have trouble reading those test strips. I have ordered a TF 100 test kit .

Thanks Brad
Sorry if I haven't worded that very well.

 

[jblizzle]

The key drivers are the pH and the CH.

TA is just a buffer for pH ... if it is higher the pH will rise faster. The levels they recommend for TA are more appropriate for pucks (which are acidic and will hold the pH down).

Having the low CH can actually be damaging to plaster finishes as well as it can pull the calcium out of the plaster.

I would trust the values recommended here ... although if it impacts your warranty, then you need to take that into consideration.

Kind of an advanced topic, but, If you learn the poolcalculator.com, at the bottom you can see the CSI ... too low and it will pull calcium out of the plaster, too high and it can result in scaling deposits.

Be sure to post up when you get your test kit.

 

[ping]

The Australian Standards are a little different than the US Standards so you will get different values. Here at TFP our recommended ranges work for most pools.

We suggest the TA to be 60-80 range for SWG users because this range tends to lock in the pH for a longer period of time. With the TA in the 120-140 range, your pH will most likely constantly raise and you will have to add acid more often.

We suggest to keep the pH in the 7.5-7.8 range due to the SWG also. If you have to manually add your chemicals then you must have a range and not just 7.4. You would have to add acid everyday or so to maintain your pH. SWG's tend to make the pH rise and by having the pH a little on the higher side you should use less acid overall to control the pH.

Your CH is already at 250 and is fine. If you have hard water, you will want to keep a close eye on the CH as this along with the pH is a big factor in scaling. If it does get high, then you will have to run a lower pH to help with the CSI index.

Follow the FC/CYA guide in Pool School, pool-school/chlorine_cya_chart_shock, and you will have a great looking pool all the time. Your manual suggest to keep the CYA in the 30-50 range due to the Australian Standard, but here in the US, our manuals say to keep the CYA in the 70-80 range. Your SWG will not have to work as much if your CYA is 80, and that will help to slow the rate of pH rising.

Use the pool calculator, http://www.poolcalculator.com/, to figure how much of each chemical to use and to figure out the CSI of your pool. By running your CSI near 0 or slightly negative, you should not get any scaling.

 

[duraleigh]

Stick with TFP. Pool stores suggestions are usually not correct in some form or another. Australian water is the same as US water and these guidelines have been developed to work.

Blending pool store advice and TFP advice almost always leaves the pool owner in the befuddled middle.

 

[jblizzle]

Australian water is the same as US water

But the sun must be different. I mean if the pool stores here think the sun in the mid-west is different from the sun in FL or AZ ... then it must be VERY different down-under. I mean the light waves are upside-down!!!!!

 

[Blue114]

Thanks for all your advice. The pool is very cloudy ATM because of the fine particles that came off when I acid bathed it. I'm running the filter 24/7 to try to clear it up. When I get my new test kit I'll run all the tests and post on this site.

Yes it is the other side of the world... the sun is the same but sometimes I wonder what stops the water falling out of the pool!!

Brad

 

[Blue114]

Hi again,

Finally got my TF-100 test kit and have the following readings.

FC 2
CC .5
PH 7.8
TA 170
CH 240
CYA 85

So I have some adjusting to do. I will use The Pool Calculator
Thanks
Brad

 

[chiefwej]

Stick with TFP. Pool stores suggestions are usually not correct in some form or another. Australian water is the same as US water and these guidelines have been developed to work.

No, the water there spins the other way when going down the drain, so it must be very different.

 

[Blue114]

I am getting closer to the balance I want

FC 5
CC 0
TA 120
CH 240
PH 7.2 ( I'm aerating to get to 7.6 )
CYA 70

One question. If I leave these figures as they are (PH at 7.6) it give me a good CSI index (0.24) as per The Pool Calc. but in the recommended figures for SWG in pool school it says its important to keep the TA at 60-80. By doing this it makes the CSI at 0.5 - 0.6 roughly.

Would I be oK eaving the TA at 120? as I have had real problems with calcium on the floor and walls and have just finished clenaing it off.

Thanks

 

[jblizzle]

Couple questions.

Did you actually replace water to get you CYA to drop or was that just testing "error"?
Did you mean to report that the CSI numbers were negative? Since a lower TA would lower the CSI (more negative).

Leaving the TA high in conjunction with the SWG is going to make you pH rise rather quickly requiring acid addition often.
I might think you would be happier lowering the TA closer to 80ppm, raising the CH up to around 350+ppm, and then keeping the pH 7.5-7.8

 

[Blue114]

Hi jblizzle

Yes ,I have been backwashing a lot and refilling to get rid of the sediment in the water from when I acid bathed the pool. It is slowly clearing up.

You were right ,the CSI numbers were supposed to be negative.

Thanks. I'll keep workinh on lowering my TA

Brad