Am I thinking correctly?

[Reed Kadavy]

CYA in my 13,500 pool/spa is 90. I am currently keeping my CL at 10 on the high end which reduces to 6 over 2 days. If I were to replace enough water to reduce CYA to 60 and kept CL at 6 on the high end would my CL reduce to around 3.6 over a two day period?

 

[ajw22]

CYA of 60 you need to keep your CL at 7-9 and at a minimum of 5. You will need to add CL every day or two. Use this chart for FC levels - [FC/CYA][/FC/CYA]

 

[domct203]

CYA in my 13,500 pool/spa is 90. I am currently keeping my CL at 10 on the high end which reduces to 6 over 2 days. If I were to replace enough water to reduce CYA to 60 and kept CL at 6 on the high end would my CL reduce to around 3.6 over a two day period?

You should be following the FC/CYA chart.

Pool School - Chlorine / CYA Chart

If your CYA is 90ppm, your daily target is 10-12ppm, and you should never allow the FC to go below 7ppm.

If your CYA is 60ppm, your daily target is 7-9ppm, and you should never allow the FC to go below 5ppm.

What you suggest is allowing the FC to go too low and will result in an unsanitary pool.

When manually dosing the pool with bleach, you should be checking/adding daily.

 

[Dirk]

Which is why, if you look at the signature of my post and the two posts above, you'll see we all use SWGs...

With your pump and solar panels, you could really make good use of a Pentair bundle, like this one:

Pentair Easy Touch 4PSC-IC40 W/ Salt Cell - 520593 - INYOPools.com

There are many models to choose from, one that would be right for your pool and equipment configuration...

 

[Reed Kadavy]

I am sort of at a crossroads. I’ve used liquid 10% chlorine for the past 12 months after fighting the prior 9 years using chlorine tabs. Boy what a difference. My chlorine cost for The year is $255. I haven’t enjoyed daily testing, but I stuck with it and wonderful water and no algae problems at all.

Now I have to decide between a Stenner pump or switching to SWG. I know the pump and tank is probably $500. I have an EasyTouch panel. Would I then need an IntelliChlor power center along with the SWG? That looks like about $900.

It’s probably a toss up money wise with a new generator about every 3 or 4 years, but I know more than one neighbor that had a salt water pool that is back using tabs due to problems with their SWG and they didn’t wish to spend the money to rectify. Probably not a smart move on their part.

It seems you can get good results either way with the hassle of using liquid chlorine compared to the possible issues of the SWG and it’s power center. It appears there are TFP advocates on both sides.

 

[ajw22]

With a SWG you basically buy a few years of CL with one payment for the cell.

Get the Stenner pump if you enjoy the trips to the store to load up on CL jugs.

Life cycle costs for either is about the same.

 

[Dirk]

The cell is consumable. The transformer is not. So it's $900 up front, then about $500 for replacement cells. As pointed out, the overall cost compared to chlorine is about a wash. But... that's if the cell doesn't fail. I'm on my third one in just over a year. Others here report of problems with theirs, too. And Pentair's built-in (replaceable) flow switch is a real piece of junk. So I can't pretend the SWG solution is without possible problems. I don't know what percentage of Pentair SWGs fail. They have a two year warranty, if you have the initial install done by a pro (you can do the subsequent cell replacements).

SWGs stop working in cold water. So depending on where you live, you'll have to manually dose chlorine some months out of the year. That is their primary disadvantage. Chlorine demand typically goes down during the same months, so it's not like dosing in the summer.

Stenners can work all year 'round, but you still have to buy chlorine, store chlorine, worry about freshness and load the hopper. Plus there is the initial cost.

I'm using a combination of a Pentair SWG and an IntellipH (acid dosing). They work well together and offer some niceties that Stenner systems don't. When they work, they work great. I haven't touched a pool chemical since I put them online in June. (Well, except to pour acid into the hopper a couple times.) It's been quite luxurious. I test every few days, but have gone as long as 11. I think you could conceivably get away with once a week, depending on bather load. If you have to add muriatic acid often, the combo is something to consider.

 

[Reed Kadavy]

Thinking about SWG in Gilbert AZ, with my solar heat I’m pretty sure I can keep water temp at least in the 50’s during the winter. Would this be adequate to keep a Pentair SWG in operation maybe with extended pump time?

 

[mknauss]

My IC40 stops producing chlorine around 58F. Typically mid December.

At that time, I only add LC once a week or so. Lasts for about six weeks.

 

[Dirk]

From the manual:

Temperature Sensor: To protect the IntelliChlor SCG from operation and potential damage when the temperature of the pool water falls below 52° F, ±3° F (11° C, ±1.67°C), the temperature sensor switches the IntelliChlor SCG off, illuminates the COLDWATER light and no chlorine will be produced.

But Pentair ICs are fussy, so as Marty can attest, your actual cutoff temp may or may not be within spec. You'd just have to try and see. I did contemplate running solar so that I could continue to use my SWG longer, but where I live I doubt it would work, as my water can get into the 40s. For me, the electricity cost and wear and tear wouldn't be worth the effort it takes to dose manually, even if I have to do so four or five times a week.

I'm still producing here. But I haven't lived through a winter with my SWG yet, so I don't know exactly what to expect in terms of dates and temps.