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

[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?

[PoolDoc]

Do you have a K-2006 or an HTH 6-way drops kit? If so, what are your calcium and alkalinity levels?

[JimK]

Do you have a K-2006 or an HTH 6-way drops kit? If so, what are your calcium and alkalinity levels?

Calcium is about 240, TA is 90-100

[JimK]

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?

Do you have a K-2006 or an HTH 6-way drops kit? If so, what are your calcium and alkalinity levels?

Calcium is about 240, TA is 90-100

Hi Ben.

I let the bucket sit another 24 hours and now the water is clear. The only thing I see is white sediment on the bottom of the bucket. What do these results mean? Anything useful?

BTW, a clarification/correction; the calcium level I mentioned above is actually the "Total Hardness" per pool store testing. The TA figure is from my own testing using a Taylor kit (the figure is unadjusted for CYA which is 80 per my own test using Taylor kit). Today I purchased the Taylor reagents needed to test for calcium, but need help with that (see my post in the appropriate section).

[waterbear]

Today I purchased the Taylor reagents needed to test for calcium, but need help with that (see my post in the appropriate section).

FYI, I answered that post.

[JimK]

FYI, I answered that post.

Thanks. I'll take that conversation over there.

[JimK]

Hi Ben.

I let the bucket sit another 24 hours and now the water is clear. The only thing I see is white sediment on the bottom of the bucket. What do these results mean? Anything useful?.....

Hi Ben.

I know you are really busy and I greatly appreciate your help with doing the bucket test for metals.

Waterbear helped me with problems I was having reading the Taylor calcium test kit results ( http://www.poolforum.com/pf2/showthr...lcium-test-kit ). I appears my calcium level is 250ppm max.

So to summarize, my TA is at 90-100 (NOT adjusted for a CYA level of 80; don't know what the adjusted level would be) and Calcium is at 250ppm max. After waiting an additional 24hrs. the water in the bucket is now clear with only white sediment visible on the bottom (sides of bucket are also white).

Let me know what you think when you get a chance.

[PoolDoc]

You did the bucket test. You added bleach -- to break down any phosphonates, and then oxidize any metals to the insoluble form, and then soda ash, to raise the pH to the point where they would precipitate.

Colors tell the tale: iron would make the sediment brown or orange; copper blue or green, or maybe black. You got tan. That means calcium plus maybe a tiny bit of iron. You *might* have other metals, but it's unlikely.