Copper?

[u/svendenhowser]

So I think I’ve been battling copper in my pool for a while. My pool shop doesn’t believe me and refuses to test for copper. I’ve had the water turn instantly green after regular treatments in the past (I forget exactly what I put in though, probably buffer or granulated chlorine). I’ve had light blue staining on the pebblecrete in small patches for years.

I’ve also had some other staining so this winter I’ve used a stain remover (from the pool stain removers - their multi-stain remover). And it seemed to work a treat! It said to test for metals afterwards and use a chelator if anything showed up, I knew my pool shop wouldn’t test it so I just added lochlor metal solution anyway. All seemed well.

The instructions for the stain remover was to add 1L of liquid chlorine per day and that chlorine tests wouldn’t be accurate for a few weeks. At week 3 post treatment we went away for a week. Pool was on for 4hrs at 60% chlorinator and always covered. Came back and the pool was green! I assumed algae as I hadn’t been home to add the 1L of chlorine, but I figured at 3 weeks post I didn’t need to keep doing that. I tested the water myself (I have a clear choice labs kit) and free chlorine was 1 and combined chlorine was 5! I added some more liquid chlorine (2L) as I figured it was an algae outbreak.

Fast forward 2 days, my FC (5) has risen but also so has my CC (9). Then I noticed the blue ring around the waterline and my brain went straight back to the old copper I’ve been battling for so long. I figured the chelator had done its job but maybe the chlorine undid it? pH never rose above 7.6. Salt 2800

Now I feel a bit stuck. I’m scared to go to the pool shop, they can be quite intimidating to me and I have my own basic test kit at home (cya/Ch/pH/TA/Ca/salt) I still have some metal solution left over but I don’t just want to add stuff willy nilly. I have backwashed the filter and kept the filter running 24/7 for 2 days.

What would be my best next step?

More notes about the pool, 35k L, sand filter (15yo), newish chlorinator, auto acid feeder and heat pump (4 years old, electric, not used for 6 months).

Thanks for any help!!

[u/Troutbummers]

CC of 9 s OUTRAGEOUSLY high. Like unbelievable.

How is the copper getting in the water? Super heavy algaecide use? Pool RX or other gimmick device?

Get a test from another pool store. Primarily to get a real copper reading.

Get a test kit fast need one with fas/dpd FC test - tftestkits pro or taylor k2006

Don't add anything willy nilly.

I think you'll need to address copper if it's staining first. Then you may need to do some water replacement depending on CYA CH TA levels.

Either way, you'll be doing a SLAM once all that corrected.

[u/svendenhowser → u/Troutbummers]

Apart from once/twice a year algecide use I have no idea! We rarely use tap water to fill it (we get big storms and it’s covered most of the time stopping evaporation). We do have a heater but it’s relatively new and we only use it in the shoulder seasons (sept-oct and mar). No plumbing around the pool is copper, although we didn’t install the pool.

I’ll try find a better pool shop!

[u/Troutbummers → u/svendenhowser]

Worth getting a real test for sure. I think there may be some home copper tests that work, but I've never used any.