Filling a resurfaced fibreglass pool

AussieSwimmer

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Hello wonderful people, ive just had my fibreglass pool resurfaced and I need help on filling/balancing.

Ive tested the tap water and got -

FC - 0
PH - 7.4
CYA - 0
Salt - 0
TA - 50

Should I add the salt (8 bags) and leave SWCG off til its dissolved and add liquid chlorine? Assume Ill need to lift CYA straight away? Adjust TA or wait and see how PH settles? Run filter 24/7? Any advice would be appreciated.

Also I can fill on tuesday, could I have it ready to swim by Friday (christmas day)?

Thank you!!
 

setsailsoon

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Aussie,
Did the refinish company have any recommendations or conditions to avoid? If not, I'd get some FC in that water.
As I recall you can get some pretty hot and sunny days this time of year in Perth (gorgeous place!). So you should also get your CYA level up. No need to mess with TA just yet. Focus on pH, FC, CC for now.

Yes, you do need to also get your salt up to the correct level before you power up the salt cell. The salt will dissolve pretty quickly but it doesn't disperse as quick as other chemicals and tends to layer on the bottom. So definitely run the pump for 24 hours to disperse before powering up the cell. How are you testing salt level? The read outs on salt cell are notoriously inaccurate. Don't know if you can get a Taylor K1766 down there but it's the best salt test.

Chris
 

ajw22

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Your water is good enough to go swim in today.

Add salt, stabilizer, and liquid chlorine. Add the stabilizer using the sock method. Dont let any visible salt or stabilizer sit on the pool floor. Keep brushing it around until it dissolves.

Your TA is fine.

SWG off for 24 hours after salt is added.

I like running pump for 24 hours for a few days after adding salt or stabilizer.

Go swim and enjoy your pool.
 
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AussieSwimmer

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Thank you both for great advice! Yes Chris...got a few 38 deg (C) days coming up this week!
 

Dirk

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Have you already filled the pool? Or are you going to be filling it next Tuesday?
Are you confident in the water volume number for your pool? Or has it always been "just an estimate?"
Do you have a water meter that measures the water you buy from your supplier?
 

AussieSwimmer

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Filling on Tuesday...fairly confident on size but could be a good chance to measure...ill check the meter before and try to use as little water in the house as possible. Thanks!
 

Dirk

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Oh, you'd heard that one before! :) Be sure your irrigation system doesn't run while filling...
 

AussieSwimmer

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Do I wait til the pool is full before adding chemicals? Or do i add salt and chlorine gradually as the pool fills up? Wednesday is 39deg C and im worried about algae?
 

Dirk

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Most municipal water supplies have a little chlorine in them (Have you tested your fill water?), plus the water itself won't have any algae or organics or pathogens that would "seed" an algae outbreak. You'll be fine waiting for the fill to complete, then test for FC, then bring the pool up to your target FC level with liquid chlorine.

Then add your CYA. Continue to use liquid chlorine until you can measure target CYA. Depending on how you add it, it can take days or a week or more to show up in a CYA test. Or... if you're confident with your water volume, you can add the correct amount of CYA based on a calculation, and it'll be in there, even if you can't get a test result to match for a few days. Then add salt.

Test the pool for salt before you add any, the fill water may have some salt in it already. After you add the salt, let it mix in well for at least 24 hours or more. Maintain your FC with liquid chlorine for a day or two after adding salt. Test the salt again and adjust if needed. That resets the clock and you need to wait another day or two. Repeat until you get to your target salt level. Then turn on the SWG. You don't want "patches" of low-salt or high-salt water passing through an active SWG.
 
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AussieSwimmer

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Hi guys, pool is going great until today after a backwash, theres a brown stain at the old water level. If i scrub with a cloth it lightens but doesnt completely lift. Any ideas??? I was building a gazebo and a metal pole fell in the pool and i didnt see it til an hour or so later...could that be the cause? Please help!
 

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mknauss

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Doubtful the pole would start to add iron to a pool that quickly. You can try some vitamin C tablets in a sock on the stain if you wish to see if it iron.
Can you get a Magic Eraser? That should work.
 

AussieSwimmer

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Hi people, its been a few weeks now since I filled my pool and im trying to balance the water still.

FC 7.5
CC 0
PH 7.8
TA 150
CH 125-150
CYA not sure but stabilizer added when pool filled.

Im having trouble reducing FC, ive turned down my SWCG but it isnt really reducing much at all. Ideally Id like FC at 4-5ppm.

Am i right in assuming my PH and TA isnt accurate with my FC high @ 7.5?

Do I need to adjust TA or CH?

Thank you!
 

cowboycasey

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I keep my FC between 7 to 9 at all times with my SWG... your TA and PH are fine at that level, don't worry about PH until FC over 10...

Your CH is a little low but I would not add any, what is your fill level? your TA is a little high but it will come down by adding acid to reduce your PH, you can do it faster by aerating and dropping it with acid... You will just be adding acid more with a higher TA...


Hope this helps :)
 

ajw22

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You can’t say if your FC is high or low without knowing your CYA level. CYA determines FC using FC/CYA Chart

All of your other tests look ok.

pH test is only invalid if FC over 10 when using Taylor pH test.

Have you read ABCs of Pool Water Chemistry?
 
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setsailsoon

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Aussie,

Congrats on the new pool finish. I'll just say ditto what Allen said. Your question on FC implies you don't know about the FC/CYA relationship and I respectfully recommend you learn this soon. In hot Australian summers this is especially important. I'm sure our TFP Aussies will confirm this. Your pH and TA are not affected with FC at 7.5 significantly. 10 ppm FC is the level we say impacts pH measurements with the liquid color test. Even at that level the impact on pH test is often very minimal but it is the thresh hold where results are changed enough to start to matter.

If it were me I would leave everything where it is, your chemistry is fine for now. Worry more about FC getting a little low than potentially a little high. I say "potentially" because you really don't know what correct is 'till you get a CYA reading as Allen indicates. Focus on measuring your CYA and then get back to us with the results.

I hope this is helpful.

Chris
 

Dirk

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AussieSwimmer

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Ok thank you all for so much prompt and infortative information.

Just tested CYA and only got 40ppm which is low!

Tested FC again and its now 7ppm.

Does this sound right? How quickly would the FC drop with CYA at 40?

Thanks!!!
 

Dirk

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Too many variables! CYA is only one factor in chlorine consumption:
- CYA level
- water volume
- surface area of pool
- water temp
- air temp
- sun exposure (hours per day, and angle)
- swimmer load
- organic content (how much gunk is in the pool)
- filter status (how clean or dirty)
- SWG settings (output and runtime)
- age of chlorine (if you're supplementing)
- presence of algae

You learn your pool. FC loss per day is going to be what it's going to be, and it'll be different almost every day, and will certainly vary seasonally. Quoting one of our experts (Pat): "Generally we say an FC demand of 2-4 ppm in a 24 hr period is acceptable."

I suspect that is a summertime rate. Where I'm at, now that its winter, I'm losing about 0.5 ppm per day.
 

Dirk

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As mentioned, your other tests results will be fine with an FC of 7.5, and 7.5 is not too high right now. As you know, a CYA of 40 is low for an SWG pool. For a non-SWG pool your target FC would be 5-7. Keep inching your CYA up, 70 is a good place to be. And you can keep inching your FC down, 5 will be a good target once you get your CYA up. So for now you're right on track.
 

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