- Nov 15, 2018
- 188
- Pool Size
- 19000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Monarch ESC24 / ESC7000
FC 9
CC 0
TA 90
CH 290
pH 7.65
Salt 4700
B 55
The basic chemistry hasn't changed except I added borates about a month ago.
I did an initial test on 14th of Nov and CYA was ~40. Dosed it up to 70. Re-tested 27th of Nov to confirm. Pool store reading was the same (so 70. They are good for a cross check).
Periodic tests since then held relatively stable. Noticed ~13th Feb it was down to 60.
Re-test yesterday and it's < 30.
Check CYA reagent with 50ppm standard and it's "about right". Not convinced so I mixed up a 70ppm standard using fresh granular CYA. Re-test pool and both standards tonight.
Same result.
So sometime in the last 4 odd weeks something has eaten a pile of stabiliser. Colour me quite perplexed.
I tested the water about 4 times using different bottles of reagent, and both at pool (23C) and room temperature (30C).
So I'll dose it back up over the next couple of days, but this is most peculiar. We've had nothing out of the ordinary. I did hit the pool with a pile of Cal-Hypo to knock out what looked like Mustard Algae living in the bottom of the pool which pushed the FC up to about 28, but it was passing OCLT both before and after.
Salt level has risen, so it's not a water dilution issue.
CC 0
TA 90
CH 290
pH 7.65
Salt 4700
B 55
The basic chemistry hasn't changed except I added borates about a month ago.
I did an initial test on 14th of Nov and CYA was ~40. Dosed it up to 70. Re-tested 27th of Nov to confirm. Pool store reading was the same (so 70. They are good for a cross check).
Periodic tests since then held relatively stable. Noticed ~13th Feb it was down to 60.
Re-test yesterday and it's < 30.
Check CYA reagent with 50ppm standard and it's "about right". Not convinced so I mixed up a 70ppm standard using fresh granular CYA. Re-test pool and both standards tonight.
Same result.
So sometime in the last 4 odd weeks something has eaten a pile of stabiliser. Colour me quite perplexed.
I tested the water about 4 times using different bottles of reagent, and both at pool (23C) and room temperature (30C).
So I'll dose it back up over the next couple of days, but this is most peculiar. We've had nothing out of the ordinary. I did hit the pool with a pile of Cal-Hypo to knock out what looked like Mustard Algae living in the bottom of the pool which pushed the FC up to about 28, but it was passing OCLT both before and after.
Salt level has risen, so it's not a water dilution issue.