Help! - Black streaking in year old plaster

[Claygirl74]

We had our plaster pool resurfaced just over a year ago. It looked perfect last season. We did not cover the pool over winter and tried to maintain minimum chemistry levels and left the pump running. I assumed light algae would come out when we slammed the pool at the start of the season but it looks terrible.
I slammed for almost a week keeping numbers where they needed to be using my Taylor 100 test kit. Most of the algae disappeared but there appears to be some light greenish staining plus all this terrible black streaking (see images)
I don’t know what to do next, we are new to owning a pool and I don’t want to make it worse. The dark streaky areas do have a rougher texture to the plaster than the clearer areas adjacent to them.
I would love to hear some thoughts on what to do here.
Pool numbers today: (we just had weeks of rain so my CH is lower than it had been, I need to go get calcium)

FC-3
CC-0
PH-8
TA- 80
CH-300
CYA- 30

 

[proavia]

What does "maintain minimum chemistry levels" mean?

For CYA 30, your FC needs to be 4-6. FC/CYA Levels
Dose for the high side of target so you don't fall below minimum before your next chlorine addition.

I see you have PoolMath lonked to your forum account, but there are no test results, only some chemical additions.
What was your CYA last fall? Was the FC maintained all winter for that CYA level?

Adjust pH down from 8.0 to 7.6 - 7.8

CH of 300 is good for now. And if you use CalHypo to chlorinate (as you have kn the past), it will also add CH.

Do the black spots have a different texture than the rest of the pool?

In a nut shell, lower the pH into the 7's, increase FC to high side of target for your CYA and brish the entire pool daily.
Never let the FC drop below minimum for your CYA.

 

[Rancho Cost-a-Lotta]

Have you used any products containing copper such as algaecides, solid forms of chlorine w/ additives, ionizers, Pool RX etc?

 

[Claygirl74]

Have you used any products containing copper such as algaecides, solid forms of chlorine w/ additives, ionizers, Pool RX etc?

I don’t think so? I use Pool Life NST prime chlorine tabs and Turbo Shock Shock treatment, and occasionally liquid pool chlorine. No algaecides or ionizers. I’m not sure what Pool RX is? I have added CYA, calcium etc. but only what has been recommende

What does "maintain minimum chemistry levels" mean?

For CYA 30, your FC needs to be 4-6. FC/CYA Levels
Dose for the high side of target so you don't fall below minimum before your next chlorine addition.

I see you have PoolMath lonked to your forum account, but there are no test results, only some chemical additions.
What was your CYA last fall? Was the FC maintained all winter for that CYA level?

Adjust pH down from 8.0 to 7.6 - 7.8

CH of 300 is good for now. And if you use CalHypo to chlorinate (as you have kn the past), it will also add CH.

Do the black spots have a different texture than the rest of the pool?

In a nut shell, lower the pH into the 7's, increase FC to high side of target for your CYA and brish the entire pool daily.
Never let the FC drop below minimum for your CYA.

By maintaining minimum I meant that over the winter when when the pool was uncovered and unused I tested every few weeks ( during the season because I’m new to pool ownership I test and adjust almost every day) keeping the chemistry within the range TFP pool math gave me. Some weeks if it rained or there was a small buildup of leaves for example I would need to add more chemicals because it had fallen slightly out of the target range.

Last fall my CYA was 40, but this spring it was low. I added 5 lbs about two weeks ago and now it is at 30.
Yes the plaster where the streaking is does have a slightly rougher texture.

Thank you for the information.

 

[proavia]

I don’t think so? I use Pool Life NST prime chlorine tabs and Turbo Shock Shock treatment, and occasionally liquid pool chlorine. No algaecides or ionizers. I’m not sure what Pool RX is? I have added CYA, calcium etc. but only what has been recommende

By maintaining minimum I meant that over the winter when when the pool was uncovered and unused I tested every few weeks ( during the season because I’m new to pool ownership I test and adjust almost every day) keeping the chemistry within the range TFP pool math gave me. Some weeks if it rained or there was a small buildup of leaves for example I would need to add more chemicals because it had fallen slightly out of the target range.

Last fall my CYA was 40, but this spring it was low. I added 5 lbs about two weeks ago and now it is at 30.
Yes the plaster where the streaking is does have a slightly rougher texture.

Thank you for the information.

Thanks for that info.

Don't forget to update PoolMath witha current set of test results.

Let's see if someone has any ideas on the black streaks and what they might be.