Salt Water Tested… what should I add first and last?

[raytse]

hi All,

Just get my SWG salt water at 3800ppm, which is good as RJ60+ expect 3500 - 4000ppm.

Here is my water tested with K-2006C:

FC - 3ppm
CYA << 30 (still see the dot even fill up to top)
TA - 120ppm
pH - 8.0 (And i am targeting 7.5)
CH - 200ppm (I have Plaster Pool , do I really need higher CH?)

Before adding Liquid Chlorine and tuning my SWG, I want to balance the water to SWG recommendation.
What chemical I should add first? Next and Last?

Thanks!

Ray

 

[TinFoilHat]

For a salt water pool you want your CYA between 60-90 so you definitely need to add, per Pool Math, the appropriate amount of granular CYA via the Sock Method. In the meantime, your FC is dangerously at the lowest minimum you would want so you should immediately bump it up to 6 ppm for your CYA of 30. That will probably be 1/2 to 1 gallon of liquid chlorine, again rely on Pool Math. Don't use the SWG for achieving this level as it is intended to be a maintenance tool for your FC. You do not want it to drop below 4 so until your CYA is adjusted you need to monitor it daily. After adding CYA you can measure it again 24 hours later.

 

[raytse]

Thanks… but how about the pH , TA and Hardness? Should I deal with that before CYA adjustment?

 

[bgollmer]

Ignore TA as it will stabilize as you address PH.
FC and PH you should be testing daily. When PH gets near 8, knock it back down to mid 7s with muriatic acid.
You can add liquid chlorine and muriatic acid about 30 minutes apart.
Add stabilizer next until CYA is in the 60s.
Last would be CH wouldn't hurt to increase to 300.
Don't overshoot CYA or CH targets or you will be stuck draining water.

 

[raytse]

cool .. the adjustment sequence would be :
FC (by liquid Chlorine) -> Ph (Muriatic acid) -> CYA (Stablizer) -> CH

 

[setsailsoon]

hi All,

Just get my SWG salt water at 3800ppm, which is good as RJ60+ expect 3500 - 4000ppm.

Here is my water tested with K-2006C:

FC - 3ppm
CYA << 30 (still see the dot even fill up to top)
TA - 120ppm
pH - 8.0 (And i am targeting 7.5)
CH - 200ppm (I have Plaster Pool , do I really need higher CH?)

Before adding Liquid Chlorine and tuning my SWG, I want to balance the water to SWG recommendation.
What chemical I should add first? Next and Last?

Thanks!

Ray

I've done this a couple times and I like to get the FC level up to a couple ppm above target range and then adjust pH. You should do FC and pH adjustments daily for a while. I'd also get your CYA at least 60 ppm so your FC loss will be reasonable this time of year. After you get lined out here you can turn on the swg. Initial settings can be estimated using Pool Math in the "effects of adding" section under the button top left corner. Assume 3-4 ppm loss from sunlight and disinfection. Below is a screen capture to show you how to do this. You can play around with run time and % to match your needs. You're gonna want to get a vs pump as soon as you can afford it. It pays for itself in a year at my power costs and in California it would be quicker. You can just run the pump at high speed long enough to keep the pool clean then turn it down to min flow for your pump which is usually around 1700 rpm and it's a big power saver.

Getting back to your swg... if FC level rises or drops make a small change to run time or power then let it run a day or two. Don't try to over control it or you'll go nuts. FC should cycle over a couple ppm range depending on all kinds of factors. You want to line out at high end of target so swings never take you below min FC. You should get this pretty lined out in a week or so. Then you're on your way to pool easy street the TFP way. No more jug lugging chlorine! Check FC, CC, pH daily 'till you get to know your new salt pool. Eventually you be able to back off to a couple times per week.

I hope this helps.

Chris

 

[raytse]

Thanks Chris.. Yes, CA electricity charges is insane…. planning to get a VS pump soon.

 

[setsailsoon]

Incidentally, here's a screen clip from Pool Math set up for your pool. You can play around with run time and % power as you see fit. I have found this to be very accurate to set up your swg. Once lined out, I found I could adjust run time about once per month and % power was constant for the first 3 years. During summer months run time increases and at other times it drops way down. After a couple years operation FC production will drop over the years as your swg wears out which will require increase of % power. Eventually you can't keep up during the summer and that means it's time to replace the swg. I think one of the best ways to make it last long is to keep within TFP ranges and adjust them to control csi to be slightly negative like -.02 or so. If you can do this and avoid deposits so you don't have to clean the swg it will last a long time. Cleaning removes the very thin layer of catalyst that is plated on your swg surface. The catalyst is used to drive production of FC. Without it you don't make much FC.

I hope this is helpful.

Chris

 

[raytse]

Definitely helpful Chris. Thanks for sharing your SWG expereince, it saves me a lot of trial and error effort.