Some Newbie SWG and related questions

[markcw97]

Friends,

Brand new pool owner here. Details in signature. No issues yet -- the water is clear, warm already, and my family is loving it!

Waiting on my Taylor 2006 test kit to arrive tomorrow, but here are some pool-store tests from yesterday:

FC 3
TC 3
TA 45
PH 7.2
CYA 70
CH 25 (60 the previous day at another store)

I know I need to raise the TA and PH (I already added about 6 pounds of baking soda), but can anyone tell me what washing soda or soda ash are? Please tell me I can get it somewhere other than a pool store? ;-)

Both stores warned me about my extremely-low CH -- one said my liner was likely to deteriorate and crack. But I read here in Pool School that it is not really a concern for SWG above-ground pools?

I know that my mileage may vary, but what would be a good starting point for how many hours per day to run the SWG? The default setting of 20 seems high. I lowered it to 10 after the first day, and hope to test it myself tomorrow.

Going forward, I expect I will need to add CYA occasionally, and possibly some chemicals to adjust PH/TA -- in my scenario, would you expect my PH/TA to tend to drift up, or drift down? Any other chemicals that I should have on hand ready to use when the occasion arises?

One store suggested shocking your pool once a week. Am I completely clueless? I thought if you kept your numbers in good shape, you wouldn't need to ever shock it, except during Spring startup? If I misinterpreted that, please help me understand!

Thanks so much!

 

[Jimrahbe]

Mark,

Welcome to TFP...

Your pH is just fine, I'm not sure why you are screwing with it. Anything between 7.2 and 7.8 is ok. Although your TA is low, with a SWG, both your pH and TA will soon rocket up there, so for right now I would leave them alone.

My understanding is that with a liner pool, CH is not relevant, so let's see what other here say about that...

I have three pools and have never "shocked" any of them in the last three years. As you say, if your numbers are good, you should never have to add shock.

Assuming your above numbers are good, which we have no way to tell at this point, your FC of 3 is at the absolute minimum you want to be. You should really be trying to maintain an FC of 5 or 6 ppm.

See this.. Chlorine CYA Chart

You need to run your pump for how many hours it takes to generate the required amount of Chlorine. So, you either need to run your pump more, or increase the percentage output of your SWG. It is much better to generate too much and then cut back, then it is to generate too little and try to catch up.

Thanks,

Jim R.

 

[YippeeSkippy]

Ohmy. Those pool stores are cluelss. You're correct- vinyl lined pools don't need calcium *unless they have a heater* and the heater needs it. And the only reason a pool "needs shocking weekly" is to sell more product!

I'd start at 6 hours at 50%, and then daily testing. If you want to run it more just cut down the SWG %, and if you only want to run the pump less just turn the % up. You'll find your happy place pretty soon. Here is one guide to recommended levels--> Pool School - Recommended Levels

Washing soda can be found in the laundry aisle, often next to the Borax. It comes in a box.

 

[pooldv]

More about pool chems here, Pool School - Recommended Pool Chemicals

 

[markcw97]

Thanks for the good advice!

Got my new Taylor 2006 Kit today and here are my first results:

FC 3.2
CC 0.2
pH 7.8
TA 100
CH 30
CYA 50

Looks like I need to raise both FC and CYA in the near future. Should I add bleach or rely on the SWG running longer to bring up the FC level?

My SWG does not have a percentage setting -- only the number of hours to run until it turns off. It only ran 10 hours the last two nights, so I bumped it up to 16 hours for now. Side question: with an over-the-edge-of-the-pool SWG, is it strictly necessary to have the pump circulating water in the pool while the SWG is on? (So far I have always had the pump/filter running)

Is my TA now too high? I know the pH is on the high end.

Let me know your thoughts, and Thanks!

 

[mgmoore7]

Hello
Your minimum FC for a CYA of 50 is 4. Anything below that will lead to something growing / unsanitary conditions.
Pool School - Chlorine / CYA Chart
Use Pool Math to determine the right amount of bleach. Do not wait on the SWG.

TA is fine for now.

With a SWG pool, CYA is recommended at 70-80. If your pool season is not much longer, I am not sure that I would worry about it this year if your SWG can keep up but it may not be able to with the .4lbs of Chlorine that it generates per 24 hour period. See the chart. With a daily loss of 2ppm of FC, you need to run it 14.5 hours per day. If you are loosing 3ppm per day, it needs to run about 22 hours. See the chart. Your pump should be running at the same time.

PS: the SWG is undersized for your pool.

I would do a OCLT to ensure there is nothing growing and you don't need to SLAM. To do this, raise your FC to 8 using Pool Math and turn off the SWG an hour before you do the test after the sun goes down. Keep the pump running and keep the SWG off.

 

[markcw97]

This is great info, Matt.

I did not know what my unit output was, so that and the calculator are very helpful -- thanks for creating the spreadsheet and making it available to use TFP peeps!

They are advertising the SWG as good for up to 20,000 gallons, but that is marketing-speak, obviously!

-- Mark

 

[mgmoore7]

This is great info, Matt.

I did not know what my unit output was, so that and the calculator are very helpful -- thanks for creating the spreadsheet and making it available to use TFP peeps!

They are advertising the SWG as good for up to 20,000 gallons, but that is marketing-speak, obviously!

-- Mark

Yes, it is fine assuming you want to run it 24/7. Definitely marketing speak.

TFP recommends 2 to 3 times the stated capacity. On my 12k pool, i have a 40k capacity unit, wish i had a 60k fo my situation.