Refilling small pool - do I need liquid chlorine while I wait for SWG?

[jyo1]

Hi All,

I am a new-ish pool owner and shifting now to the TFP method after realizing our pool-maintenance person has been managing our pool poorly. I'm excited to dive in to this!

Our pool has CYA well above 100+ so I'm planning on draining and re-filling the pool. Nothing like a "fresh" start!

My question, do I need to use liquid chlorine for the couple of days required to refill the pool, wait for added salt to dissolve, and turn the SWG back on? Or can I simply just 'stick it out' for those couple of days, get the chlorine levels appropriate using just the SWG, and then balance everything else out? The pool itself is pebble-tec and was completed about 6 months ago.

Our pool is small - 6000 gallons, and is covered by a dark-colored retractable pool cover. We're in Los Angeles.

Thank you for the help!

 

[Mdragger88]

Definitely Use liquid chlorine daily until your swcg is up & running - you don’t want algae
Follow the liquid chlorine chart
FC/CYA Levels
With a cya that high you may already have algae brewing so after refilling do an
Overnight Chlorine Loss Test at target fc levels for your cya to determine if you need to do the
SLAM Process.
Swcg’s are great maintainers - but they cannot overcome an algae problem nor be expected to make up for an fc deficit.

 

[jyo1]

Thanks! Will do.

Our current FC levels are currently at 15 so hopefully that's kept the algae at bay.

 

[pjt]

Perform the diluted CYA test to get an idea of your actual CYA level.

CYA - Cyanuric Acid Test

Cyanuric Acid (CYA) is the chemical name for what is commonly referred to as Stabilizer … Read more…

www.troublefreepool.com

You might be able to perform a partial drain and fill to save on water and chemicals.

 

[jyo1]

I'll try the diluted CYA test tomorrow!

If I replace approximately half the water in the pool, should I expect CYA levels to also decrease by (roughly) half?

 

[pjt]

If I replace approximately half the water in the pool, should I expect CYA levels to also decrease by (roughly) half?

Yes, it's exactly proportional.

 

[jyo1]

Even the diluted CYA test failed to register on the Taylor test.

Assuming the test functions in the same directly proportional way I would expect, then based on the difference between yesterday's test and today, I'd guess CYA is somewhere between 200-300.

I'm going to drain-off 90+% of the water and refill.

Would've been a nice day for a swim! Thanks all for your advice.

 

[jyo1]

An update and a few questions!

We've just completed refilling the pool. As expected, FC = 0, CYA = 0.

I've initially added bleach per the Pool Math app to get FC up to 2ppm.

Tomorrow I'll add CYA and more bleach. I'll leave the opaque cover on the pool until I do that.

My questions I'd love another set of eyes on:

1. PH appears to be close to 8 per the Taylor test now (I didn't expect it to be that high, but I ran the test twice). Maybe the water in Los Angeles is very basic?

How much do I need to worry about that.. tomorrow? Should I just get Chlorine and CYA levels in order first, and worry about PH in another day or two?

2. This pool has an SWG. Is there any reason I shouldn't add the ~148lbs of salt that Pool Math recommends tomorrow and get that process started?

Thanks again for all the help!

 

[Mdragger88]

You can go ahead & get ph in the 7’s now or tomorrow. Its no major rush but should be done.
Test your fill water ph, ta, & ch & make note of them as they will continuously affect your pool chemistry when you replace water lost to evaporation.
Don’t add all the salt poolmath calls for as you don’t want to over shoot. Aim for 3/4 of what it says, let that circulate for 24-48 hours & test your level to see where it got you then add more if needed and test again 24 hours later.
Creep up on the target.
(Read your swcg manual for your target)
Same goes for cya. Put 30ppm worth in a sock & hang in front of a running return. Squeeze to dissolve it.
Test cya in 24 hours.
Don’t wanna overshoot.
As soon as the sock is in the water start chlorinating for 30ppm cya. (6ppm)
& tomorrow night/the following AM do an
Overnight Chlorine Loss Test to rule out anything funky before you go raising cya past 30/40ppm.

 

[jyo1]

All of that makes sense and a good reminder not to overshoot on the CYA + salt. Thank you!

 

[HermanTX]

This pool has an SWG. Is there any reason I shouldn't add the ~148lbs of salt that Pool Math recommends tomorrow and get that process started?

@Mdragger88 covered majority of it. Some additional info
Do not turn on SWCG while adding salt - high concentrations of salt going through the SWCG when it is on can cause alarms
Do not try to use the SWCG to increase FC to the recommended level. Use LC to raise FC to the recommended level and then let the SWCG “maintain” the level of FC per the recommended levels for your CYA. So if you are losing 3ppm per day to UV and pool use then have the SWCG replace that 3ppm daily.
Please see
FC/CYA Levels