Salt Cell Replacement

[asumrall]

Hello all!

I just moved into a house with a new pool that uses a SWCG. Never used salt water before so I'm trying to figure out the best way to fix my issues. We had our liner replaced and filled with water last week and I just got my test kit in Taylor K-2006 with the Taylor K-1776 salt test. I currently have our SWCG running at 100% and the chlorine level has maintained between a .5-1 every time I test it with the exception of running the "Super Chlorinate" function which bumps it up to about a 5. I'm thinking my problem is the Cell Size which is listed below.

Current Set-Up:

Pool Size - 24k Gallons
SWCG - Goldline Aqua Rite with T-9 Cell (rated for 25k gallons)
Pump - 1 HP AquaShield running on 110 volts
Filter - Not Sure exactly because I didn't take a picture but its a sand filter and I think Hayward brand

Last Test Results from last night:

Salt- 3400
TC - 1
FC- 1
PH - 7.7
TA - 80
CYA - Very low - was unable to test because I think it's either 0 or my eyes are old.

Is it as simple as swapping our T-9 Cell to a T-15? I don't want to have to continue to run the SWCG at 100% to maintain a 1 TC. If I can just replace the cell with a larger unit that's what I'd rather do but I want to make sure the SWCG can put out enough Chlorine with the bigger cell to justify spending the hundreds of dollars!

Thanks for listening and let me know if I left anything out!

P.S. Disregard my signature, that was my mother in laws pool before we got one!

 

[ajw22]

Cya need to be 60-80 for SWG to operate properly. CYA acts as sunscreen for CL. You are losing the CL your SWG is creating to the sun UV rays.

You need to add 224 oz of stablizer according to PoolMath. You should also use liquid chlorine to get your FC to 5. Then your SWG should maintain that FC level. See FC/CYA Chart

When your cell wears out you can replace it with a T-15 cell. No reason to do that now. Just run it at close to 100%.

I suggest you review ABCs of Pool Water Chemistry

 

[Jimrahbe]

A,

You have a couple of issues...

First, with zero CYA, any chlorine that your cell does produce will disappear pretty quickly. With a salt system your CYA should be 70 or 80 ppm.

Second, as you already know, your cell is on the small size for your pool. Not only will you have to run it close to 100% but you will need to run your pump 24/7, which I assume you are not doing.

Third, you seem to believe that an FC level of 1 is ok, but it is really low..

To fix your signature, just go into "Setting" and then "Signature" and update to your current pool as a bad signature is worse than no signature at all. It will just confuse people.

The first thing you should do is increase your CYA level. I would add 4 lbs of CYA in lady's Knee high stocking.. But the stocking in the skimmer or better yet hanging in front of a return. Squeeze the sock a few times a day until it all dissolves. Then remeasure your CYA. Four lbs should bring your CYA up to about 20 ppm.. Once you know can get a good reading on your CYA, then continue adding CYA until you get it up to 70 or so..

You can just install a new T15 cell in place of your T9, but that by itself is not going to solve your issue. If you change cells, you also have to change the setting inside your control system from T9 to T15.

Thanks,

Jim R.

 

[JamesW]

The T-9 produces about 0.98 lbs per day, which provides 4.9 ppm per 24 hours at 100%.

Assuming a 3 ppm per day demand, you would need to run about 14 hours per day to generate enough chlorine.

A T-15 produces about 1.47 lbs/day, which provides 7.3 ppm per day.

For 3 ppm per day, the runtime would need to be about 10 hours per day.

So, that's a difference of 4 hours of pump runtime per day.

Assuming a power usage of 1,000 watts, that's 4 kilowatt hours per day.

At 10 cents per kilowatthour, that's 40 cents per day or about $12 per month.

As noted, you should address the cyanuric acid and then do an OCLT to determine if a SLAM is needed.

 

[asumrall]

I know a TC of 1 isn't ideal but considering a CYA of 0 and the fact that there isn't much demand for it right now it should get me by until I get my issues fixed. I will add CYA starting today and also some liquid Chlorine to boost the TC level. I am also running my pump 24/7 due to the fact the SWCG is needing to constantly run for any chlorine to remain in the pool. The pool has only had water in it since Saturday so I haven't neglected it too long.

I am familiar with what is recommended chemical wise as I converted my MIL's pool to a trouble free pool a couple years ago and have had nothing but success with it (fortunately). You all are 100x more help than a pool store and I thank you all so much for your help.

I will add CYA and CL immediately and just run the pump 24/7 until the cell goes out. It will run my electric bill up but better than a green pool.

Thanks again for your answers and advice, as always.

 

[asumrall]

The T-9 produces about 0.98 lbs per day, which provides 4.9 ppm per 24 hours at 100%.

Assuming a 3 ppm per day demand, you would need to run about 14 hours per day to generate enough chlorine.

A T-15 produces about 1.47 lbs/day, which provides 7.3 ppm per day.

For 3 ppm per day, the runtime would need to be about 10 hours per day.

So, that's a difference of 4 hours of pump runtime per day.

Assuming a power usage of 1,000 watts, that's 4 kilowatt hours per day.

At 10 cents per kilowatthour, that's 40 cents per day or about $12 per month.

As noted, you should address the cyanuric acid and then do an OCLT to determine if a SLAM is needed.

Thank you,

I will fix the CYA and do an OCLT after I get it up to the recommended levels. Thank you all again!

 

[YippeeSkippy]

My take on this is that you were mistakenly assuming the SWG would bring you up to a desired FC level on its own. It won't since its competing with the sun and anything in the water that needs to be oxidized.

You should use some liquid chlorine or bleach any time you need a fast boost (new water, someone has an accident in the water, dead deer in the pool, that sort of thing) and let the SWG work to *maintain* that FC level.

Maddie

 

[splashpad]

CYA - Very low - was unable to test because I think it's either 0 or my eyes are old.

Was this test done in the daylight? Either way, I would aim for 30ppm (PoolMath based on your pool size and go from there

P.S. Disregard my signature, that was my mother in laws pool before we got one!

If you manage 2 pools, you can have them both in your signature

 

[splashpad]

I will fix the CYA and do an OCLT after I get it up to the recommended levels. Thank you all again!

The OCLT will need the SWCG turned off for "true" results.

You can also do a "quick test" FC demand test, add FC 10ppm (from Liquid Chlorine/Bleach) (PoolMath) and retest in 15-30min, see if it's at/near 10. You can do this before and 24hrs after adding CYA, so that you can note the difference in FC duration