I've got a mess - please help.

[B_Mann]

As I've said in my SWG conversion post, I have recently purchased a home with a pool that was previously maintained by an unqualified neighbor. There is some sort of "algaecide/copper" product that he put in the water that Im having a really hard time getting cleaned out.
Anyway, there was 0 FC when I converted it and the CYA was off the chart high.
Well, I got busy with work for a couple of days and left the SWG set to 90%

Now my FC is 45.
I just did a diluted CYA test, and it is 200!!!
I've already done about a 50% water exchange to try and get this down.
1. Is this safe to swim in?
2. How can I get the CYA and FC lowered?

Any advice is greatly appreciated!

 

[mknauss]

1. Is this safe to swim in?

Technically, yes. With a CYA of 200, safe to 80 ppm FC. Not sure I would swim in it, though.

2. How can I get the CYA and FC lowered?

Drain the pool and refill. Do an exchange if you are concerned of the pool shell floating.

 

[Orion7319]

As I've said in my SWG conversion post, I have recently purchased a home with a pool that was previously maintained by an unqualified neighbor. There is some sort of "algaecide/copper" product that he put in the water that Im having a really hard time getting cleaned out.
Anyway, there was 0 FC when I converted it and the CYA was off the chart high.
Well, I got busy with work for a couple of days and left the SWG set to 90%

Now my FC is 45.
I just did a diluted CYA test, and it is 200!!!
I've already done about a 50% water exchange to try and get this down.
1. Is this safe to swim in?
2. How can I get the CYA and FC lowered?

Any advice is greatly appreciated!

Unfortunately your going to have to change more water if your CYA is that high. Am I correct that you have a fiberglass pool? If so you can’t drain that your have to do a water exchange.

Draining - Further Reading

www.troublefreepool.com

 

[B_Mann]

Technically, yes. With a CYA of 200, safe to 80 ppm FC. Not sure I would swim in it, though.

Drain the pool and refill. Do an exchange if you are concerned of the pool shell floating.

Is there a table here somewhere for the CYA/FC ratio for safe swimming levels? I see people talking about CYA levels and FC levels, but I cant seem to find the source of that info?

Will these levels not deplete over time? Our water is billed x2 b/c Im on city sewer/water, and is VERY expensive.

 

[mknauss]

I cant seem to find the source of that info?

FC/CYA Levels
See SLAM levels. It is essentially 40% of CYA level.

 

[B_Mann]

Unfortunately your going to have to change more water if your CYA is that high. Am I correct that you have a fiberglass pool? If so you can’t drain that your have to do a water exchange.

Draining - Further Reading

www.troublefreepool.com

I do have a fiberglass pool.....

 

[B_Mann]

FC/CYA Levels
See SLAM levels. It is essentially 40% of CYA level.

Thank you. I bookmarked it.

 

[mknauss]

Will these levels not deplete over time? Our water is billed x2 b/c Im on city sewer/water, and is VERY expensive.

CYA will deplete 5 to 10 ppm per month. But your issue is keeping algae from forming. Your minimum FC is 15 ppm. You cannot test pH at that level reliably. So you are in a dilemma.

You can try to limp along, maintain very high FC, get a pH pen to test pH, and use rain fall (drain down several inches before it rains) and might get your CYA down. But if the pool turns cloudy, your done. Time to exchange.

 

[B_Mann]

CYA will deplete 5 to 10 ppm per month. But your issue is keeping algae from forming. Your minimum FC is 15 ppm. You cannot test pH at that level reliably. So you are in a dilemma.

You can try to limp along, maintain very high FC, get a pH pen to test pH, and use rain fall (drain down several inches before it rains) and might get your CYA down. But if the pool turns cloudy, your done. Time to exchange.

I'll do another exchange now.... Thank you for your help.

 

[B_Mann]

Last night I did an approximate 50% exchange.
CYA this morning - 190
FC 25

The guy before me must have dumped an astronomical amount of cya straight into the pool and it's lingering throughout? Packed in the sand filter? I just dont get it....

 

[mknauss]

Let it mix some more. Brush the pool really well.

 

[B_Mann]

Let it mix some more. Brush the pool really well.

ok, while im letting it mix and filter, should I turn the SWG back on?
Should I use the pool or stay out of it?

Also, the 7 way valve is letting water push by and waste while it's on "filter". Not a lot, but some. Are those rebuildable or do I have to buy a new valve?

 

[Bperry]

Last night I did an approximate 50% exchange.
CYA this morning - 190
FC 25

The guy before me must have dumped an astronomical amount of cya straight into the pool and it's lingering throughout? Packed in the sand filter? I just dont get it....

He probably was using trichlor pucks to keep algae at bay and the super high CYA forces you to use more chlorine to do that. If his chlorine source was pucks, it’s a cycle that builds fast.

Also did you do the 2:1 or 3:1 diluted CYA test? You might try doing another one to make sure it wasn’t 300ppm or higher.

 

[B_Mann]

He probably was using trichlor pucks to keep algae at bay and the super high CYA forces you to use more chlorine to do that. If his chlorine source was pucks, it’s a cycle that builds fast.

Also did you do the 2:1 or 3:1 diluted CYA test? You might try doing another one to make sure it wasn’t 300ppm or higher.

I dont know the brand of chlorine he was using, but it was a pentair model 300 off line bromine feeder that I removed.
I know he struggled to keep it from turning green - he blamed the nearby pine trees, and said thats why he kept the algaecide / copper in the pool.

I did a 2:1 diluted CYA test. It tested at 90, so that is a 180 CYA level if Im not mistaken.

 

[mknauss]

You need to continue to add chlorine, so turn the SWCG back on.
You can use the pool. How does the water look?
The MPV can be rebuilt. See MPV Valves - Further Reading

 

[Bperry]

I dont know the brand of chlorine he was using, but it was a pentair model 300 off line bromine feeder that I removed.
I know he struggled to keep it from turning green - he blamed the nearby pine trees, and said thats why he kept the algaecide / copper in the pool.

I did a 2:1 diluted CYA test. It tested at 90, so that is a 180 CYA level if Im not mistaken.

Ah. So you converted it from a bromine pool? I’m not familiar with the conversion process.

 

[B_Mann]

You need to continue to add chlorine, so turn the SWCG back on.
You can use the pool. How does the water look?
The MPV can be rebuilt. See MPV Valves - Further Reading

Ever since I switched to SWG, the water has been beautiful.

 

[B_Mann]

Ah. So you converted it from a bromine pool? I’m not familiar with the conversion process.

He said he was using chlorine tablets he got on sale a few years ago... He showed those to me, they look like hockey pucks, but they were in a bag, not the original bucket....

This is the feeder I removed

 

[mknauss]

I doubt it was a bromine pool. A bromine pool will not register any FC as it is used to activate the bromine.

 

[Bperry]

He said he was using chlorine tablets he got on sale a few years ago... He showed those to me, they look like hockey pucks, but they were in a bag, not the original bucket....

This is the feeder I removed

Feeder is chlorine/bromine. The hockey pucks were likely trichlor which have CYA in them.