Starting with TFPC in the Netherlands

[koffie]

This is my second season, the first season started with the build of the pool.
I have a rectangular vinyl pool, size 8m x 4m and 1.5m deep. About 40k liters of water. I use a SWG.
Last year I did checks with a aquacheck and stips, this year I want to start with my TF-100 testkit.

Current values of my first testings:
pH = 7.2
FC = 1.5
CC = 0.5
TC = 2.0 (I assume I have to add up FC and CC to get FC?)
TA = 60/70
CYA = 0

I did the test for CYA, after watching the instruction video. My liquid stays clear so the dot never disappears. I have never used any stabilizer , so that explains the zero (assuming CYA is allways zero unless you add some chemical?).

Some pool chemicals are harder to get in The Netherlands. I found this stabilizer : http://www.pooltopper.nl/onderhoud/...-8-kg-chloor-stabilisator-voor-zwembaden.html it seems the type I should use? Can anyone give some prediction for the amount I should use ?
I allready have found a source for baking soda, started to use that previous season to raise TA.

In the first year that I own the pool, I never had any big trouble with the water. During swimming season I run the SWG for 1 to 2 hours per day. Allmost no other chemicals are used, only some pH plus or minus to adust pH, and some baking soda. I hardly use any anti-algae at all.
At the end of the season I lowered the frequency of SWG hours (accordig to readings from simple drop tests and strips), and when the water got below 15 celcius I stopped SWG at all. I run the pump for at least 4 hours a day, sometimes more when it was freezing.
When I opened the pool, everything was fine, clear water and no swamp.

 

[Richard320]

That's the stuff!

Using Water Balance for Saltwater Pools and Poolmath (Note: upper right side you can switch to metric) I see 3.4 Kg is needed to get to the recommended range. I'd suggest starting with only 3 Kg and check it in a week or so to see if you need any more. If you've ever used any powdered chlorine in there, you might have some amount of CYA that's too low to measure. More instructions on using Poolmath.

And congratulations on the test kit. A decent test kit is a hard thing to find in Europe. Any questions on test procedures can probably be answered with the video how-to's.

 

[koffie]

Thanks for answering
I only used some tabs in the very first day during building, but thats a year ago. From there I only used SWG.
3.4 kilo is a lot (and expensive)! On the other hand : I assume I would earn back that money because I need much less SWG running ?

 

[Richard320]

Thanks for answering
I only used some tabs in the very first day during building, but thats a year ago. From there I only used SWG.
3.4 kilo is a lot (and expensive)! On the other hand : I assume I would earn back that money because I need much less SWG running ?

I doubt it would pay you back in electricity savings, but it helps maintain the FC level against sunlight degradation. If the pool is covered so no sunlight hits it except when you're swimming, you could probably take it to 30 CYA and have it be adequate. That would require much less CYA. Only about 1.4 Kg.

 

[koffie]

Is it reasonable to measure FC daily and calucalte how much you loose on average and generate on average witch SWG ? So that I could make estamimate loss in 1 day and calculuate how long the SWG should run to get back at desired value ?

Yesterday at 17:30 I had FC 0.5 whith only 1 hour runtime during that day. After testing I turned the SQG on for 2 hours.
Today I added 3 hours runtime. At the end of the day (19:30) my FC was 3.
All the tim the pool was covered due to bad weather (has been raining for the past 2 days).

Have not received any stabilizer yet, hope after the weekend.

edit : Forgot I know the specs of my cell, it has a output of 25 gram per hour. This should be read as 25 gram chlorine gas per hour. So according to the poolcalculator this would give me 0.6 FC per hour with 40K liters poolwater. Correct?
This seems to add up with previous recorded values : in 24 hours I went from DC 0.5 to 3, while the runtime of the cell was 5 hours (2 yesterday after testing, 3 today). 5 Hours of 0.6 FC should give a FC of 3.0 (assuming the 0.5 is used chlorine in the 24 hours).
Are these assumptions and calculations correct ?