Opened pool up and now running into problems with water balance

[lumpypossum]

Hi,
I bought a sliding pool enclosure last summer and the pool was covered from mid October until mid May. On opening in May the water was clear and at least 8°C higher than previous years, but the walls and basin were covered in green algae. When I started the pool the readings were :
FCL=0.5, CC=1.66, PH=7, TA=101, CH=102 and CYA=45 and then things started going wrong.

I installed new grids in my DE filter and loaded it up with 4.8 lbs of DE, then I started cleaning and shocking the pool with Sodium dichloroisocyanurate dihydrate tabs , the same as I have been doing for the last five years. After quite a few filter strip downs to clean the grids I noticed that there was a problem with the filter - the grids didn't seem to be coating evenly and there were large areas where the DE was clumped and the pool had turned into a cloudy blue mess. After chatting to other TFP forum members I came to the conclusion that the DE was to blame so I bought a different brand and within 48 hours the pool cleared. After another week of trying to get the water balanced by old shock techniques I decided to switch to the TFP Slamming technique. Now I have come to the conclusion that I do not understand what is happening with the pool chemistry and need the help and advice of the TFP experts. I will attach a list of the readings taken over the last 10 days courtesy of Jesse's excellent pool testing log V3.0.

 

[JVTrain]

Most folks, including myself, probably would rather not open a .zip file from an unknown source. Can you post your most recent test readings? What test kit are you using?

 

[Chasmengr]

Most folks, including myself probably would rather not open a .zip file from an unknown source. . .

x2 . . .

 

[lumpypossum]

Sorry I was trying to get the file to an acceptable size for uploading and forgot that a zip file would be unwelcome. I have now scanned the results. I am using a La Motte Color Q Pro7

 

[DMS2014]

I like your system. I am using a book. Is that a program you bought or something you just created?

 

[lumpypossum]

I like your system. I am using a book. Is that a program you bought or something you just created?

No I didn't buy it I found it on TFP search for "Jesse's Graphical Pool Testing Log"
He has obviously put a lot of effort into generating this excel spreadsheet and it works very well.

 

[JVTrain]

General observation on your testing:
As you can see your CYA is steadily rising with the use of dichlor (or are they trichlor?) tablets.

Your FC is also routinely below TFP recommended levels for your CYA level. Pool School - Chlorine / CYA Chart

Your pool needs a SLAM. See link in signature. Do you have a source for liquid chlorine (bleach) available?

 

[lumpypossum]

General observation on your testing:
As you can see your CYA is steadily rising with the use of dichlor (or are they trichlor?) tablets.

Your FC is also routinely below TFP recommended levels for your CYA level. Pool School - Chlorine / CYA Chart

Your pool needs a SLAM. See link in signature. Do you have a source for liquid chlorine (bleach) available?

The tabs were dichlor. I had to use them as I ran out of bleach.

I believe I have slammed the pool three times as shown on the chart.

So far I have used 130 litres of 9.6% bleach but perhaps I am doing it wrong. The morning after slamming I always seem to be at a very low FC.

 

[Mr Bruce]

SLAMming is not a one time event. Read this a couple of times. Pool School - SLAM - Shock Level And Maintain

 

[cpeterson70]

http://www.troublefreepool.com/threads/73298-Jesse-s-Graphical-Pool-Testing-Log-(Excel-spreadsheet)

 

[lumpypossum]

The tabs were dichlor. I had to use them as I ran out of bleach.

I believe I have slammed the pool three times as shown on the chart.

So far I have used 130 litres of 9.6% bleach but perhaps I am doing it wrong. The morning after slamming I always seem to be at a very low FC.

So I have read up again on the Slamming instructions and last night I had the following measurements:
6/30/16 10pm 0 (FC), 0.3 (CC), 7.4 (PH), 126 (ALC), 85 (CYA) so I added 34L Bleach at 22:15pm looking for Slam Fcl of 33

The readings this morning 7/1/16 9:15am are 8.8 (FC), 0.5 (CC), 74 (CYA) so to maintain the Slam I added 20.85L Bleach at 09:30 looking for slam Fcl of 29.

Should I be checking more frequently to maintain the Slam at the highest level? I will obviously have to improvise with the La Motte tester as it's FC range is only up to 10ppm but I am sure I have read that this is possible.