Why/how is my FC level so high??

[Lovrpool]

New swg pool installed...after week and a half got aquachek7 test strips out to do some testing. I know...I know...I need the better test kits. But right now, this is all I have to work with.

I was shocked when I say 0 FC and 0 TC. Asked PB if put stabilizer in. He said no. Calculated how much I needed on pool calculator. On Sat. I added 64oz (granules) (105oz was recommended) but I wanted to start out slow. Nothing else has been added to pool.

Also Sat.7am I pushed "boost" on swg which takes it to 100% purifying.

Did test strip test at 1pm:
TH 250
TC 3
FC 3
PH 7.8
TA 80
CYA 0

By 8pm TC was 10 and FC 5 (as accurate as strips can be I guess). I decided to turn off boost and leave swg at 70% overnight.

By 2pm Sun. TC and FC were both 10. I turned back swg at the default 50% setting.

Monday my TC and FC are at highest color on strip.
TH 100
TC 10 (highest on strip)
FC 20 (highest on strip)
PH 6.8
TA 40
CYA 30-50 range

Levels still the same today. No swimmers since a week ago. Solar cover on. Been upper 60 temps. Today sunny and 80 and 7am I turned swg down to 5% and no drop when tested at 5pm.

No algae noticed. Water clear.

I'm perplexed :?:

 

[linen]

We really can't say much about your test strips results since they are more often wrong then right. Do you by any chance have an OTO chlorine test...it is a drop based test that is usually on the same test block as a ph test?

For us to really help you, we need more reliable/accurate tests.

 

[Lovrpool]

I don't . I will see if I can get PB out to test tomorrow.

 

[jblizzle]

Did you order a kit yet?

Don't let the pool get away from you already.

 

[BoDarville]

Did test strip test at 1pm:
TH 250
TC 3
FC 3
PH 7.8
TA 80
CYA 0

By 8pm TC was 10 and FC 5 (as accurate as strips can be I guess). I decided to turn off boost and leave swg at 70% overnight.

By 2pm Sun. TC and FC were both 10. I turned back swg at the default 50% setting.

Monday my TC and FC are at highest color on strip.
TH 100
TC 10 (highest on strip)
FC 20 (highest on strip)
PH 6.8
TA 40
CYA 30-50 range

Your own results provide solid evidence for needing one of the Recommended Test Kits.

1. TH drops from 250 to 100 in 2 days[/*:m:2aaa2oke]
2. pH drops from 7.8 - 6.8 and TA drops from 80-40 in 2 days[/*:m:2aaa2oke]
3. Monday's FC/TC results: FC is 20 whereas TC is 10. The proper equation is FC + CC = TC. If FC is 20 then TC must be at least 20.[/*:m:2aaa2oke]

The broad swings in TH, pH, and TA should not have occurred in two days if all that was added was granular CYA. Although adding CYA will lower the pH a bit, some of that will be counteracted by the fact that pH tends to creep up in SWG pools.

The fact that your water is clear with no visible signs of algae is a good thing. But if you want to keep it that way over the long haul, you will need the proper test kit.