How do youi tell? Black? Green? Mustard?

If you google it, there are some pics out there, tho not many.

You can tell if your stain is organic by holding a trichlor puck on the stain, if it fades, it's organic. If it fades at shock level and returns when the FC levels drop back to normal, they are organic.

If it's metal, like Iron, Vitamin C will make the stain go away. If it's copper, the vitamin c will have little affect and actually might make it worse. FC levels will have no impact on metal stains or it can also make them worse.

Black Algae is round, small dots like the size of eraser and they spread out in a circular way, green algae is more suspended in the water but will also cling to surfaces. Mustard Algae is similar to green algae but it is more resistant to chlorine, and often it takes prolonged periods of higher FC and brushing to keep mustard algae at bay. Mustard Algae tends to like shady areas of the pool. Black algae is also resistant to chlorine, and it takes frequent brushing with an appropriate brush, with FC at shock level to kill it. It can leave behind nasty stains. It is very rare if not unheard of in a vinyl pool.

If you have stains in your pool and post them, we may be able to help identify them.
 
If you have stains in your pool and post them, we may be able to help identify them.

The pool water is growing clearer every day, thanks to the idea of DE in the sand filter + pumping only through the main drain.

I don't know if I can get any decent pictures of the black spots or not. But I'll try.
I dont' have an underwater camera, ...
 
I had yellowish dirt on the bottom of my pool that was like a dust storm when moved around. not that it clouded the water, but it would move and was easily stirred up. I would vacuum it up and it was back the next day. I was thinking, why is my filter not getting this dirt out. I found out later that was mustard algae. when my pool was redone in late 2007, I accidentally let the chlorine get to 0. the water stayed clear, but I got a little black dot on a rough spot around where the tile on a step was. brush off, came back. let it go for a little bit and it would have an obvious biofilm (new term I just learned ;) that made it stick up a little higher. brush off easily, would come back in a couple days. it slowly got larger, following the rough plaster path along the tile. that was black algae. thanks again to this site, I finally cleared it up by rubbing a chlorine tab on it for several days. I even brushed it hard and shocked the pool (which means I dumped 2.5 gallons of chlorine in) with no results (pre-TFP). and of course I've had green stuff too as you can see by my avatar. I never did have the pleasure of pink or anything else (that I know of anyway).
 
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Really hard to tell from the pics but my first guess is black algae.

Try the trichlor, holding or rubbing the areas with the puck to see if they change.

Have you tried brushing these areas with a plaster-type brush with SS bristles? If it is Black Algae, keeping your chlorine levels virtually nil won't take care of the problem.

In my personal opinion you will fight a losing battle if it is algae, unless you reconsider your sanitizer choices, and the alternative if its copper staining, then acid washing is probably the only option... and again, without changing your sanitation choice, you will end up in the same situation in the future...
 
Sorry for the delay -- very busy week.

Pool has a painted concrete base or bottom shell. The upper side walls -- top 3 feet or so -- are fiberglass panels. This forms a concrete shelf which requires frequent brushing and is where the black algae, i guess, likes to accumulate if it can. The ledge is too narrow for the Aquabot t2 to properly scrub for me.

I had black algae on my steps, I think, the first year. I eliminated it there using a powdered pool shock. Dumped about an 1/8" worth of stuff all over the steps, and left it, so it dissolved slowly and was in direct contact with the stuff.
I think I'm going to have to do the same thing on the ledge/shelf.

I know I can't be perfectly chemical/poison free. But I am as close as I can get.

The D.E. in the sand filter is still helping to continually clear the water better and better.
The other day the T2 came up almost clean. So the bottom and sides are finally at a base level of clean.
But, yesterday we had two sets of families over to use the pool. Last night's robotic cleaner pulled a lot of crud again.
I also got in and went around scubbing diligently with a synthetic floor brush, which disturbed a lot of algae from cracks, and around the pool light.
Cu level is not rising either, even though I am doing a better job of cleaning the electrodes of the Floattron. If I can't get to .1 ppm, I think I'm not going to get a new center post when this one runs out and rely on other means, like a residual .05 ppm Chlorine?
 

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You already know from previous discussion our position on low levels of chlorine, anything below 2 is not acceptable IMHO, and most of the experienced folk on this forum would agree with that position. .5 is basically zero. You want to rid your pool of algae once and for all, then maintain the FC according to the CYA chart. But of course that would mean having chlorine and CYA in your pool.
 
I am not going to discourage your ozone use but here are some facts to consider:

1. It takes about 6 grams/ hour running 24 hours per day to oxidize your pool. The ozonator is nice and I have one myself but you don't have enough oxidation which leads to a residual organic load which leads to ...
2. I would guess that the primary food source for your black algae is the organics and associated nitrates in your water. If I had to guess I would bet your ammonia or nitrate level is high. You can avoid this situation with more oxidizer. You can fix it with a LOT of long term shocking or drain and fill the pool.
3. If you are concerned about chlorine exposure, first look at your own shower. A 10 minute hot shower gives you a much higher chlorine exposure on municipal water then probably a couple hours of pool swimming does.
4. The goal for your pool water is to keep it sanitary and clean.
5. Your ozonator plus 0.5 a 1.5 ppm FC COULD keep it sanitary under very limited conditions such as light short term bather load with no kids urinating in the pool or hairy dogs jumping in etc. However once you exceed these boundaries you are not sanitized anymore.
6. The presence of a high organic load with incomplete oxidation has a propensity to generate some forms of carcinogenic compounds. For this reason and others you need more complete oxidation. This can be done wiu ozone (very expensive) or with chlorine (cheaper).
7. Your pool needs a persisting residual oxidizer to prevent algae growth. This takes a whole lot more chlorine than what is required just to provide immediate sanitizing effect.

I will stop rambling.
Others on the forum can speak of the issues associated with ionizer use.

Good luck
 
I understand completely the desire to not use chlorine and only use Hydrogen Peroxide bleach in my house. What exactly is your reason for objecting to chlorine usage? I know what my reasons are but don't want to taint your answer. You do realize the negative impacts of ozone generation too, right?

Our local water company was providing pure well water without chlorination or flouridation, but because of political pressures by DENTISTS of all things they started poisoning our water.

Showering 10 minutes a day is exposing me to chlorine, so I do not worry about the pool chemistry using chlorine. It may be necessary to produce more ozone since it seems like it is not killing all the organics.

You could use MPS monopersulfate shock instead of the chlorine based solution, but if you are opposed to all chemicals you are pretty limited. Not all chemicals are bad. Lots of these chemical reactions are going on inside our bodies everyday.

I use the ozone system and MPS only in my spa and it works for that volume quite well. After numerous discussions on here I will not use it in pool sized volumes.
 
Aaargh !! this is my third try tonight.
Why no chlorine?

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I am a bit of a naturalist/conservationist. I drive a Prius because of the low emissions and high fuel economy. I used to drive a Geo Metro for the same reason. I'm also an experimentalist, and of the scientific western mind: "show me", "prove it", "Let's see what happens", "Can I do it if I try", etc. I could, and have, spent many minutes and pages explaining why I want to try to go chlorine free. It has nothing to do with blind following blind, as some would try to paint me. It has nothing to do with romantical passionate want blinding me to facts and reality. If I could have a safe pool of simple rain water, that's what I'd do. We even use the backwash water to help water our plants.

Tell me, what would happen to that bee if I used the BBB method? He'd probably die. He might not even stop for the drink, and I would miss a miracle of nature. What would happen to the frog that has adopted our pool for a home? I just hope I don't end up with a water mocassin as well.

Unfortunately, since I seem to have some black algae, and we don't really want the algae in the pool, as it eats the concrete, I'm going to have to resort to some pretty potent poison = dry shock, which will screw up the naturalness of the water, darn. But, well, that's the price. (I'll remove the frog first.) And I don't want to spend any more time justifying or discussing one way or the other, logic or lack of logic. I'd rather people just wait and see how my experiment works itself out, and what conclusions I/we can draw from it.

I also want to continue learning, asking questions, and getting reasonable answers. I have observed over the years that as I bravely ask questions, others seem to learn from the answers as well, having been too timid to ask, or not knowing how to pose the question to get a useful answer.

I think this is short and complete enough.
 

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