Green algae in random spots

[Talostown]

Hi. I have an ~30k gallon vinyl pool with an SWG. I am unable to get rid of the algae consistently. There are times it will subside then other times it starts to pick up again on the walls/deep end removable ladder stairs. The pool water itself is mostly clear, a little cloudy towards the deep end. The algae is on the the vinyl surface/ladder stairs. I replaced my T-15 cell (it was 14 years old) 2 weeks ago and the main board last season. SWG displays salt at 3800 and voltage/amps show it is generating. Below are the test results I ran this morning with TF-Pro Salt kit. I know the Chlorine levels are low but I just spent the last week slowly adding CYA as the pool was showing very low. Hoping they raise now that the CYA level is much better.

I am at my wits end (and a lot poorer). Any help would be greatly appreciated. BTW, the main stairs (white) will also at times start to turn orangish. If I sprinkle vit. c on them, it immediately cleans them. Thank you.

FC - 1
CC - 1.5
Calcium Hardness - 25
Alkalinity - 90
CYA - 80
Salt - 4000/4200
PH - 7.3ish (between colors)

 

[Texas Splash]

Your test numbers confirm you still have some algae to deal with. That's where we follow the SLAM Process. Based on your CYA, the SLAM FC level would be "31". Yes, it's up there, but that is the proper ratio/strength required based on that CYA. The only other option would be to exchange some water first to lower the CYA. Then after the SLAM Process you could raise the CYA back to 70.

Leave the ladder out of the water during the SLAM. Consider disassembling the ladder to inspect and clean all parts as much as possible. Inject some bleach into the areas you can't take apart.

 

[duraleigh]

The algae appears because you have inadequate chlorine. Brushing more frequently helps expose the algae to the chlorine but I suspect inadequate chlorine is your biggest issue with inadequate brushing being next.

the orangeish stain on your ladder is iron precipitating from your water........entirely separate from your chlorine issue.

 

[wireform]

Adding CYA when the water isn't doing well isn't in your favor but it is what it is. You need to slam and will now need higher FC to accomplish it. Get your salt cell running 100% to help you keep high fc along with liquid. When the slam turns the corner and water becomes clear shut off the cell and use only chlorine along with the OCLT to determine the real end of slam.

 

[Talostown]

Your test numbers confirm you still have some algae to deal with. That's where we follow the SLAM Process. Based on your CYA, the SLAM FC level would be "31". Yes, it's up there, but that is the proper ratio/strength required based on that CYA. The only other option would be to exchange some water first to lower the CYA. Then after the SLAM Process you could raise the CYA back to 70.

Leave the ladder out of the water during the SLAM. Consider disassembling the ladder to inspect and clean all parts as much as possible. Inject some bleach into the areas you can't take apart.

Thank you. Appreciate the help.

 

[Talostown]

The algae appears because you have inadequate chlorine. Brushing more frequently helps expose the algae to the chlorine but I suspect inadequate chlorine is your biggest issue with inadequate brushing being next.

the orangeish stain on your ladder is iron precipitating from your water........entirely separate from your chlorine issue.

Thanks. Which I thought was a result of a failing SWG cell and almost no stabilizer in the pool.

 

[Talostown]

Adding CYA when the water isn't doing well isn't in your favor but it is what it is. You need to slam and will now need higher FC to accomplish it. Get your salt cell running 100% to help you keep high fc along with liquid. When the slam turns the corner and water becomes clear shut off the cell and use only chlorine along with the OCLT to determine the real end of slam.

Thanks. I added it because when testing last week, it came back with none in the pool and my chlorine levels were almost non existent. I had assumed adding CYA would address the lack of chlorine with a working SWG system. Lesson learned. Thanks again.