Preparing Water for SWG

[linen]

I would probably do an Overnight Chlorine Loss Test (OCLT) to ensure you are algae free before worrying about the swg. See: http://www.troublefreepool.com/pool-school/overnight_fc_test To do this, I would bring the pool up to at least 11 ppm FC to do the test.

 

[sailor21]

Thanks!
Problem is that I don't have access to the required test kit.
I just dropped 1gal of 5% bleach and will test in an hour.
J

 

[sailor21]

Also, sunlight & heat are grueling this time of year. I have always struggled with FC in late August and September but never a drop like this.

What can you suggest to accurately test the salt?

 

[linen]

Thanks!
Problem is that I don't have access to the required test kit.
I just dropped 1gal of 5% bleach and will test in an hour.
J

Good point, hard to do the OCLT without an accurate measure of FC.

Also, sunlight & heat are grueling this time of year. I have always struggled with FC in late August and September but never a drop like this.

My guess from what you have written is you have algae and need to do the SLAM process: http://www.troublefreepool.com/pool-school/shocking_your_pool

What can you suggest to accurately test the salt?

I use the aquachek strips and they are always good enough for me. The Taylor K-1766 salt test has more accuracy than the strips, but the strips are easier, and again have been accurate enough for me. Your picture of you strips was blurry, but it sure looked like the yellow spike was indicating something up in the 3000s to me...was it not?

 

[sailor21]

Ok
I tested salt again with AquaChek. I used to put the strip on a full glass of test water and got the result mentioned above. On this one I put about 1 inch of water and it behaved completely different. It now read 3070ppm which looks more like it and I just need to put in the 20lbs of salt left.
I'll re-test in a half hour again when testing FC

 

[sailor21]

There is no visible algae at all. Maybe in the filter?

 

[linen]

Algae is not always visible even if it is in the bulk of the water. Again, I am not totally certain you have algae, but it sure seems like it. Following the SLAM process will tell you/fix it, but with out an FAS-DPD test, it will be more difficult.

 

[sailor21]

Ok,

FC at 3ppm
Salt at 3070ppm again.

Will run all night and full test in the morning

 

[sailor21]

Ok, pump ran all night and test was performed at 7:30am:
Salt = 3330ppm
FC = 0ppm
PH = 8ppm
CyA = 80ppm
TA = 130ppm
Cal Hardness = 190ppm

I'm thinking about opening the filter and cleaning it up, then test with fresh DE.

Also, can I just run the SWG and put it on SLAM mode? My cell is for far larger capacity (40K gallons).

 

[jblizzle]

It will not add the FC fast enough or also may not be able to maintain the high FC level required. Use bleach.

 

[linen]

On opening filter, unless it is not working, I would just wait to do a thorough cleaning until you are done with the SLAM process. Just backwash and replenish DE everytime pressure goes up 25% from the clean pressure. If you concern is that algae is in there, well it will also be in your pool and chlorine will take care of both.

 

[sailor21]

Thanks!
I will try some powder chlorine today and see what happens.
Maybe liquid bleach gets consumed fast with 94F weather? heat factor has been up to 102F plus this week.

 

[Bama Rambler]

Being liquid or powder makes absolutely no difference in how fast it's "used" up! Both are "used" up equally as fast. The problem with powder is that it's adding something else to your pool that you most likely don't need or want to increase in your pool.

 

[jblizzle]

With that high of FC loss overnight (was the SWG on too???), you need to properly SLAM the pool to eliminate whatever is consuming the FC. DO NOT use powdered chlorine as your CYA is already at the upper limit and you do not really need any more CH.

 

[sailor21]

Thanks!
The SWG is not on.
The odd thing is that it happened right after adding the salt. Never had a drop like this.

 

[sailor21]

Ok,

Everything back to normal.
Got the Ph to 7.5 and alkalinity to 120ppm (will continue to work it down to a good level).
Connected the SWG and this morning was having 5ppm FC at 50% SWG Output. Dialed it down to 25% to see what happens.
I guess it will take some days to get it set.
Thanks for the help!

 

[jblizzle]

I think we had a previous thread with sudden FC loss after adding salt ... rare indeed. Glad things have stabilized for you.

 

[sailor21]

Thanks! You guys are great!

I think this will be a week of tweaking the unit, but it works great so far.
The only thing I notice so far it that the Transformer inside the Aqua Plus (same as ProLogic) gets pretty hot. I just left the panel door open and now its much cooler.
I called Hayward anyway and they say it is normal for the Transformer to get hot.