Chlorine and failing SWGs.. What am I missing

[Garry]

We had our pool built about 8 years ago. In the beginning we had a Hayward T-15 SWG. The original swg and 3 warranty replacement swg's all failed in about 5 years. II would clean the cell with dilluted acid as recommended but the pool would get those "mineral deposit floaties" that would come off of the SWG plates. (Our attached spa would look like a snow globe.) I would test Chlorine and PH my self but would also take water samples to the pool store. I can not remember any outrageous test readings or chemical recommendations other than add cya, acid, or shock. Long story even longer, every time the SWG would fail the control board would say low salt. I would take it to get a test at the pool stores and they confirmed it had failed. When it was no longer under warranty I was finished. I switched to chlorine tablets and the occasional shock. Pool seemed to be fine other than it was a Salt water pool with no SWG.

Recently, We had a terrible build up of calcium on the water line and on the edge of the cool deck. There was so much I had someone come blast it off. I think this was a result of the tablets in the floater.

We have completely drained the water and started over.

Since the refill I have followed pool school and tested my water every couple of days.

We currently use liquid chlorine and a floater.

We would like to do one or the other.... (preferably swg )

1. Add Salt and switch back to an SWG if some one can tell me how to keep it from failing so quickly.

2. Continue using Liquid Chlorine if some one can tell me how to get the level to be some what stable. I add the recommended 10% liquid chlorine and test a day later only to be back at zero reading on the test.



Thank you in advance for your help.


16250 Gallons
TF-Pro test kit smart stir for pools with swg test kit
FC 0 ZERO (10 minutes ago)
PH 7.9 (10 Minutes ago)
TA 70 2 days ago)
CH 325 (2 days ago)
CYA 25 (2 days ago)
SALT 400 (11days ago ) Salt was from tap water we did not add any

 

[zea3]

Hi, welcome to TFP! You have water that is naturally high in calcium. Calcium doesn't evaporate out of the water and becomes more concentrated over time. When you have very hard water like this you need to pay close attention to your pH and keep it on the low end (7.0-7.2) to prevent scale formation. Then you won't have to have the scale blasted off your pool. Your Hayward SWG T-15 was too small for your pool, but that is probably not what caused it to fail. I will let those with more SWG knowledge weigh in on that issue.

Right now your CYA is too low, and that is why your chlorine is gone in a day. If you decide to go back to the SWG then you will need to raise the CYA to 70ppm. If you want to go liquid first then raise the CYA to 40ppm and dose the pool accordingly.
@mknauss

 

[Garry]

I do not understand that the SWG is too small. The SWG was Hayward Turbo Cell CLXcell 15w. It says it is for pools up to 40,000 gallons and my pool is 16,250.
Going forward I need to add lots of acid to lower ph to 7.0 to 7.2.
I still have plenty of chlorine pucks and packs of shock. Is it ok to use them to raise the CYA since they do raise CYA?

Thank you for your help

 

[zea3]

I apologize, you are correct about the size of your cell. I had it confused with a different cell. Each puck will add 2ppm CYA and 3.4 FC slowly as it erodes over the week. You might want to hang on to those and use them for vacations or when you have to be away from the pool a few days. A 1lb bag of dichlor will add about 4ppm of FC and 3.7ppm of CYA within a few minutes. Keep track of how much you use so you don't overshoot your CYA. Until the CYA gets over 30 you may still see FC burn off quickly.

 

[mknauss]

Welcome to the forum.
I personally could not deal with a pool in our climate without a SWCG. They make maintaining the proper FC/CYA ration a breeze. Yes, you do need to manage your water chemistry to maintain a slightly negative CSI. You also can use borates in the water which will dramatically lessen the scale created in the SWCG when your CSI gets a bit positive.

You have a great test kit. If you wish to use that tool to manage your pool water chemistry, using a SWCG will be a breeze.

We have essentially the same fill water. I have installed a water softener for our pool make up water. But have managed the pool for 6 years before that and I have never had to clean scale from the SWCG. Never.

 

[Garry]

Welcome to the forum.
I personally could not deal with a pool in our climate without a SWCG. They make maintaining the proper FC/CYA ration a breeze. Yes, you do need to manage your water chemistry to maintain a slightly negative CSI. You also can use borates in the water which will dramatically lessen the scale created in the SWCG when your CSI gets a bit positive.

You have a great test kit. If you wish to use that tool to manage your pool water chemistry, using a SWCG will be a breeze.

We have essentially the same fill water. I have installed a water softener for our pool make up water. But have managed the pool for 6 years before that and I have never had to clean scale from the SWCG. Never.

Is there a cheaper SWG that will work with my hayward system instead of an T-15?

 

[mknauss]

Is there a cheaper SWG that will work with my hayward system instead of an T-15?

There are generic brands of SWCG cells that replace the T15. Buyer beware on their longevity.

 

[mguzzy]

Is there a cheaper SWG that will work with my hayward system instead of an T-15?

Garrry of my "R"s... Welcome to the Forum

Everyone above is correct on the "Maintain your chem and your SWG will be happy"... especially Marty who deals with the same kind of fill water as you and lives in the same climate. Heed his words.. we worship them when he speaks ...

The Hayward SWGs are pretty bomb proof when it comes to SWGs. you won't have to buy a new controller if you stay with them, just a new cell. I have read a lot about the third party compatible T-15's and they are just too hit or miss for my comfort zone. When I got my replacement cell, I just bought another Hayward one, just for the consistency. It has proven to be a good choice. I think once you get a handle on your pools chem, you find the cell will last longer.. since acid washing to removed calcium deposits also reduces the longevity of the cell.

If you already have a water softener, route the fill water from there, that will keep your CA from creeping up. Its the only way to keep from having to do periodic drain and refills.