Kem Tek 338 vs Jack's Magic Purple Stuff in salt pool?

[JimK]

PAA - Polyacrylic acid, used to make disposable diapers, among other things. Google for more info.

I Googled it, found alot of stuff speaking over my head.

Is it effective?

[PoolDoc]

don't really know.

[waterbear]

It's a common ingredient in polymeric clarifiers. Because it has many negatively charged sites on the polymer chains it can 'grab' positively charged molecules and clump them so they can be filtered out more efficiently and can also temporarily bond metal ions such as calcium and magnesium so it has a 'water softening' effect. (This is why it is also added to Clorox bleach and some laundry detergent formulas since the larger "clumps do not redeposit as readily on clothes.)

Does it work? As well as any other polymeric clarifier. Overdosing can cause particles to form a colloidial suspension that is almost impossible to filter out instead of forming larger, filterable "clumps"

[JimK]

...... Overdosing can cause particles to form a colloidial suspension that is almost impossible to filter out instead of forming larger, filterable "clumps"

Guess I won't be using that.

According the Jack's Magic, one of the benefits of this is that it doesn't add phosphates to the pool like HEDP does. Do phosphates matter in a pool with with borates (I try to maintain 50ppm)?

[PoolDoc]

If you remove nearly all phosphates, algae has a hard time growing.
If you maintain 50+ ppm borates, algae has a harder time growing, though I doubt the effect is as great as with PO4<100 ppb
If you maintain constant chlorination at FC=10% of CYA, as far as we know, algae will not get started, though once established, some algae colonies will persist.

[JimK]

If you remove nearly all phosphates, algae has a hard time growing.
If you maintain 50+ ppm borates, algae has a harder time growing, though I doubt the effect is as great as with PO4<100 ppb
If you maintain constant chlorination at FC=10% of CYA, as far as we know, algae will not get started, though once established, some algae colonies will persist.

Great info.

While I haven't maintained chlorine at 10% of CYA (I maintain FC 4-5 at 60-80 CYA), I do try to keep borates at 50ppm and add a phosphate remover when closing the pool for the season to keep phosphates down. Since starting this practice many seasons ago I've not had any algae outbreaks. Someone mentioned the phosphate treatment at closing probably wasn't necessary, but I think I'll stick with it since this routine seems to work well for my pool.

Perhaps the combination of low phosphates and the addition of borates is a double wammy for algae. Although I've not tried it yet, I'm thinking I might be able to discontinue the weekly polyquat (60%) doses. Perhaps I'll try that next season since I already have my supply of polyquat for this season.

Also, if the bucket test for metals comes back negative (I'll know tonight), perhaps I can also stop, or greatly reduce, the addition of the sequestrant (Jack's Magic Purple Stuff).

Thanks again for taking the time to help us.

[JimK]

.....

Also, if the bucket test for metals comes back negative (I'll know tonight), perhaps I can also stop, or greatly reduce, the addition of the sequestrant (Jack's Magic Purple Stuff).
.......

Ben, when I checked the bucket this evening the water was still cloudy from the addition of washing soda. When first I started the test and added the chlorine, the water got cloudy, but cleared the next day (I didn't see any staining or sediments). When I then added the washing soda, it got cloudy again, but this time it has not cleared after more than 24hrs so I cannot see if there are any stains or sediments.

Any suggestions on how to proceed?