Hi Everybody!

[DavidH]

Hi Everybody!
TFP is a fantastic, cool website resource. :-D
Here are pix of my pool.

Is that Black Algae on the waterfall rock? I see this a lot on pools with rock waterfalls.

My biggest problem, other than with paper wasps (that prefer my pool water instead of the traps I set!), is CH. It does not show well in the pix I took today but I have scale all around just above water line and the Jacuzzi overflow tile looks real bad when the pump is off. The standard answer in Phoenix metro is "it comes with the territory" but my tap CH tested this AM is only 120.

FC = 5 (shocked last week and my SWG is running 10 hours at 50%, I need to reduce either the hours or % a bit in order to get my FC down a little.)
CC = 0
pH = 7.7
T/A = 90
CH = 460 (using the 30 sec. method. Up from 450 from Shasta last month)
CYA = 30
Temp = 82

It is a daily task to keep pH down, I suspect due mostly to all the bubbling from the rock and Jacuzzi waterfalls and the aerator. I am thinking about turning off the water features to minimize pH increase but that's no fun.

As I said above, I shocked last week, up to 20 FC for 3 days, but last night when I swam over by the waterfall, I see about 2 inches of green algae under one of the rocks that does not get water except maybe splash from the pool. I suspect I will have to shock again after I get rid of it?

My major concern though, is the CH. I just cleaned my salt cell last month and it already has about 1/2 calcium buildup. I am thinking about draining my jacuzzi into the pool and then backwashing it down to the bottom of the skimmer. Unfortunately, I don't have the "rinse, waste" control valve on my sand filter just "backwash and Filter."

Anyone have experience with those magnetic wraps that are suppose to break down the minerals in your water when you wrap them around the plumbing? Are those affective at all or just "Snake Oil?"

You all rock!

 

[Casey]

Hmm. Let's see.

You are running a SWG and your CYA is only 30. It should be anywhere from 70 on the lowest end to 90 on the highest end. Yours is way too low!

High pH is the most contributing factor due to calcium scaling with a high CH. The only way to bring down calcium is to do a partial drain refill which might be good, considering your fill water is on the low side. You can also try and scrub your tiles with 1 part muriatic acid to 10 parts water in a bucket.

I'm not sure what I'm seeing on the rocks. Maybe if you try and scrub them with bleach water, that may help. It could be algae.

Your pool is gorgeous though!! I'm so jealous!

 

[JasonLion]

Short term, if you raise your CYA level to around 70-80 and lower your TA down to about 60-70 that should greatly reduce the PH drift and also cut down on the rate of water line scaling.

Longer term you should think about how much water replacement you are willing to do. The underlying problem is the high CH level. You can manage high CH levels by keeping PH and TA down, or you can replace water to bring CH down. In arid areas, CH will just go up again, thus the needs to think about how much water replacement you are willing to do long term.

Try holding a vitamin C tablet against the rock for 30 seconds and see if that does anything.

 

[DavidH]

Thanks Casey. Previous owner put it in for backyard curb appeal and it snagged me. I think it helps keep home value up now too and that is good.

I tried scrubbing the rock with bleach when I shocked last week. Didn't seem to have much effect. I'll try Jason's Vit C 30 second trick and see if that works.

Looking at draining as per my original post and then adding more CYA via skimmer sock and monitoring for a few days while continuing to add acid and aerate to get TA and pH down.

Thanks Jason and Casey!

 

[frustratedpoolmom]

Avatar Explanation please....

 

[DavidH]

Avatar Explanation please....

Google Tiger Hug

 

[frustratedpoolmom]

Is that you or you just like the pic?

 

[DavidH]

Is that you or you just like the pic?

Have liked lions and tigers since I was a little tyke, but only from a very long distance!

 

[DavidH]

Short term, if you raise your CYA level to around 70-80 and lower your TA down to about 60-70 that should greatly reduce the PH drift and also cut down on the rate of water line scaling.

Longer term you should think about how much water replacement you are willing to do. The underlying problem is the high CH level. You can manage high CH levels by keeping PH and TA down, or you can replace water to bring CH down. In arid areas, CH will just go up again, thus the needs to think about how much water replacement you are willing to do long term.

Try holding a vitamin C tablet against the rock for 30 seconds and see if that does anything.

Thanks Jason!
I got my CYA up to 65. After I scrubbed off the green algae under the rocks I shocked again and backwashed to the bottom of the skimmer. It reduced my CH down to from 460 to 360. I thought that was impressive and I should be able to control it using that method. I ran the jacuzzi for 3 hours yesterday in hopes of lowering the T/A but it did not move. Have it running again today and added more acid.

1- How long must I run the jacuzzi (air blower with 7 jets) in addition to the aerator and water feature in order to get the T/A down to the 60-70 you recommend?
2- If there a danger in loosing sand with such a long backwash? I only have a 2-way filter/backwash valve.

FC 10.5 (coming off a shock)
pH 7.6
T/A 90
CH 360
CYA 65
Temp 80

P.S> Have not bought a Vit C tab yet but I did scrub the rocks and see little if any difference

thanks!

 

[DavidH]

Short term, if you raise your CYA level to around 70-80 and lower your TA down to about 60-70 that should greatly reduce the PH drift and also cut down on the rate of water line scaling.

Longer term you should think about how much water replacement you are willing to do. The underlying problem is the high CH level. You can manage high CH levels by keeping PH and TA down, or you can replace water to bring CH down. In arid areas, CH will just go up again, thus the needs to think about how much water replacement you are willing to do long term.

Try holding a vitamin C tablet against the rock for 30 seconds and see if that does anything.

Thanks Jason!
I got my CYA up to 65. After I scrubbed off the green algae under the rocks I shocked again and backwashed to the bottom of the skimmer. It reduced my CH down to from 460 to 360. I thought that was impressive and I should be able to control it using that method. I ran the jacuzzi for 3 hours yesterday in hopes of lowering the T/A but it did not move. Have it running again today and added more acid.

1- How long must I run the jacuzzi (air blower with 7 jets) in addition to the aerator and water feature in order to get the T/A down to the 60-70 you recommend?
2- If there a danger in loosing sand with such a long backwash? I only have a 2-way filter/backwash valve.

FC 10.5 (coming off a shock)
pH 7.6
T/A 90
CH 360
CYA 65
Temp 80

P.S> Have not bought a Vit C tab yet but I did scrub the rocks and see little if any difference

thanks!

Sat. morning edit. I thought the CH reading was suspect and re-tested today. It is 420 so it only dropped 40. Backwashing to drain water is not as viable an option as I thought.

 

[PaulR]

Sat. morning edit. I thought the CH reading was suspect and re-tested today. It is 420 so it only dropped 40. Backwashing to drain water is not as viable an option as I thought.

No, if you want to seriously lower your CH, you need to drain a serious amount of water. Say you drain 10% of your water and replace it with water at CH 120; your CH will end up at (.9 x 460 + .1 x 120) = 426. If you're looking for CH 300 you need to drain a lot more. If you did it all at once, that would be:

(1-p) x 420 + p x 120 = 300; solve for p, p = .4

so you'd need to drain 40% of your water (starting from where you are now) to get CH down to 300.

If you do it in stages it will require replacing more water in total, just not as much at once.
--paulr

 

[DavidH]

Sat. morning edit. I thought the CH reading was suspect and re-tested today. It is 420 so it only dropped 40. Backwashing to drain water is not as viable an option as I thought.

No, if you want to seriously lower your CH, you need to drain a serious amount of water. Say you drain 10% of your water and replace it with water at CH 120; your CH will end up at (.9 x 460 + .1 x 120) = 426. If you're looking for CH 300 you need to drain a lot more. If you did it all at once, that would be:

(1-p) x 420 + p x 120 = 300; solve for p, p = .4

so you'd need to drain 40% of your water (starting from where you are now) to get CH down to 300.

If you do it in stages it will require replacing more water in total, just not as much at once.
--paulr

That makes sense (I knew I should have paid more attention in Algebra!).

We are currently in the months where they monitor water consumption and tie that to the sewer bill so I will probably have to live with this for a while.
Thanks Paul.