Pool is clear but bottom looks spotty and dirty

[robbym70]

I am really interested to know how people remove algae without a wire brush.....

My set up is totally different than yours but when I need to scrub the walls of my vinyl pool I use a stiff nylon brush. I thought maybe switching to a stiff nylon brush might be a good alternative for you if you think the wire brush is damaging the surface of your IG pool. Couldn't hurt trying it out.

[rkrgk]

My set up is totally different than yours but when I need to scrub the walls of my vinyl pool I use a stiff nylon brush. I thought maybe switching to a stiff nylon brush might be a good alternative for you if you think the wire brush is damaging the surface of your IG pool. Couldn't hurt trying it out.

I am having a tough time removing the black algae spots even with the wire brush. I think black algae may not stick to vinyl surface as it would to a gunite surface? I have scrubbed the walls everyday for three weeks continuously while maintaining a +shock+ level of FC, I got so tired, but still there are algae spots. I think there is has to be an easy way to remove them without draining and acid wash, but I just dont know what that is. Its almost gone, and is much better now, but I would like to remove the remaining patches somehow which does not come off even with a wirbrush. I was going to try some strong algecide as my next plan.

[BigDave]

I'm sorry I can't give you a better plan, maybe some will read this who has another idea.
How's the pool surface holding up to the scrubbing? How are your numbers holding?
A couple warnings about algaecides:
Some have copper - not something most that really belongs in a pool - It can stain the pool, fingernails and blond and colored hair.
Some have ammonia which can combine with chlorine to form monochloramine ( an effective algaecide but stinky and irritating ) however a tremendous amount of chlorine will be consumed trying to overcome the ammonia and chloramines.
Some have Trade Secret - I'd never put that in my pool.

[BigDave]

Suggestions:

• Get a K2006 kit.
• Read the Best Guess Chlorine page.
• Adjust your chlorine levels to the correct range for algae killing -- use the low end of that range.
• Keep the chlorine there . . . for weeks.
• Begin brushing REGULARLY.
• Do not wear high-fashion expensive swimwear in the pool. Skin is VERY chlorine resistant; women's swimwear that costs over $100 is NOT. Such suits are made to be seen in, not to be swum in. If you use the pool a LOT, all polyester water aerobics suits are super-durable.

Black algae penetrates down into the cracks and crannies of the pool surface. Even when it seems to be gone, it's not. If you keep brushing while maintaining chlorine levels, it will be *mostly* gone 2 weeks after you can't see it any more.

But, it will not be all gone, and will recur if you let chlorine levels go low.

Note that if you have stabilizer levels above 40 ppm, and do not READ and FOLLOW the Best Guess Chart, you're mostly wasting your time. Keep in mind that test strips are HORRENDOUSLY inaccurate when use to measure stabilizer.

I just saw that Ben had provided this advice to someone asking about Black algae. Perhaps we didn't need to go to +shock+ level but other than that we're consistent.
Please resist the urge to "throw stuff at it". Doing so will most likely make it much harder to clean.

[rkrgk]

Thanks BigDave for sending me the post from Ben.
My problem is that the remianing algae does not come off the pool surface at all. I was hoping there is an easier way to make chlorine reach these pores so that there will be progress when I scrub next time.

As I mentioned I did make lot of progress, whatever I could remove with my brush I removed them. And my numbers are not looking that bad (dont know why I dont use much Chlorine overnight with some black algae present still).
This is what I got yesterday evening and this morn.
FC - 8.5 (no change from last night)
pH - 7.8
TA - 150
CH - 400
CYA - 40ppm
Borate - 30ppm

As you can see I also added some Borax thinking it might help me control algae in the long term. I am ading some pics with this. Some of the spots that you see in the pic could be the shadow not the black spots. As you can see the walls and bottom are pretty clear of algae, but there still some.

pool_pic_after_sruubbing1.jpgpool_pic_after_sruubbing2.jpg

[BigDave]

It makes sense that the overnight FC wouldn't change much with so little of the algae's surface area left exposed to chlorine.
I think Borate is a good choice - maybe a little higher. The pH might be getting a tad high (especially with 400 CH). Muriatic Acid is a good way to bring it back down - Be sure to read and understand:Using Muriatic Acid to Safely Lower Your Pool's pH.

[rkrgk]

It makes sense that the overnight FC wouldn't change much with so little of the algae's surface area left exposed to chlorine.
I think Borate is a good choice - maybe a little higher.

Yeah, I was following PoolDocs writeup on increasing to 50ppm, I got only 5 boxes of borax last time, I am planning to add 5 more, thats the reason my pH was a little off too.

The pH might be getting a tad high (especially with 400 CH). Muriatic Acid is a good way to bring it back down - Be sure to read and understand:Using Muriatic Acid to Safely Lower Your Pool's pH.

I did reduce the pH to 7.4 in the last two days.

I also got the polyquat 60 from amazon. And planning to add and see if it makes any difference. and may be get some trichlor powder and sprinkle directly on top of the black spots and brush if I can.