Re: Brown deposits on pool bottom
I do not understand the chemistry of vinyl liner fading so do not know exactly what level of chlorine will start to fade a liner. It has been written elsewhere on this forum that low pH does more to damage and fade a liner than chlorine, but obviously very high levels of chlorine can bleach dye out of most anything (as several pieces of my clothing with spots on them will prove -- I never wear anything good outside anymore when I dose with chlorine, no matter how careful I am).
Now that said, your CYA level of 40 will tie up most of the chlorine and in theory this chlorine tied up (combined with) CYA should not affect your liner, but I can't be certain of that.
I also do not know definitively precisely what level of disinfecting chlorine is needed to kill this mustard/yellow algae. It has also been reported elsewhere on this forum that using a polyquat algicide will help kill this stuff though generally the philosophy of this forum is to use chlorine whenever possible and save the extra chemicals only when needed (and this may be one of those times).
Refer to this chart and notice that to get 1-2 ppm of disinfecting chlorine (at a pH of 7.5) that appears to be needed to kill this algae, you would need (at 40 ppm CYA) somewhere around 25-35 ppm FC. Keep in mind that this will only give you the equivalent of 2-4 ppm FC if you were not using CYA, but again I do not know if this would damage or fade a liner (my guess is that it wouldn't if only exposed over a week or so -- a year, well maybe).
If you want to play it safe, you could try the polyquat algicide to see if that helps, especially if you are concerned with your vinyl fading. I personally don't think you'll run into a problem with the 25-35 FC level, but then again I don't have a vinyl pool nor your situation. If you do decide to go the "chlorine-only" route, start out at 25 and slowly work your pool up to 35 only if needed and please let us know what happens.
Sorry I'm not more definite about this.
Richard
P.S.
Your web-site is really nice!
Re: Brown deposits on pool bottom
Since I had to up my chlorine every august to 30-35 ppm when this stuff set in, I can tell you from experience that for the week or so that you need to keep the high chlorine settings, your liner will not fade, you probably get more fade from one month worth of sun.
Re: Brown deposits on pool bottom
I'm having the same problem with my ag pool. It started about 2 weeks ago. I got in to vacuum as cold as the water is this time of year and after I ran the filter for about 2 hours, I saw the same brown algae-like substance on the bottom but mostly in the middle area. My water is also a cloudy blue after vacuuming. I'm going to try doing a super shock but would like to know how much de to add to my sand filter. This stuff definitely seems to be blowing back in. When I backwash after vacuuming, there is only clear water coming through the hose. I'm also going to try using a filter saver (nylon skimmer sock purchased from In The Swim catalogue). Hopefully, if I vacuum with this sock in place, it will catch some of that dam BROWN STUFF. I've had an ag pool for the past 15 years with no problems but the past 2 years have been a nightmare. I didn't know that you could add de to a sand filter.
Re: Brown deposits on pool bottom
Back in mid July I posted the same issue and ultimately feel my filter is at fault and that this is not algae. We all seem to have Hayward sand filters, I don't know of any form of algae that just settles, it either is in suspension or attaches to something.
I know with my filter I can feel a slight suction on the return jet when I backwash and it took 7 days of 24 hour filtering to remove the cloud after spring shock so I'm pretty sure I have a bad spider gasket. Closing for spring I vacuumed to waste to remove the brown wonder and so far, 2 days later, nothing on the bottom. I will continue to check it over the next few weeks and report back.
Can someone siphon some out, put it in a glass and then shock the glass water and see the results? This should determine if it's organic or not.
Wayne
Re: Brown deposits on pool bottom
Wayne, this stuff we're talking about is DEFINITELY a type of Algae, it starts like deposits in spots, if left unattended, it gets to be more and more, what you don't really notice (until you start to vacuum) is that the whole floor will get a thin layer on it - it's so even that you think your remaining liner is spotless, however, turn the vac on and see the color difference. The walls also get it - more on the walls with shade and relatively hard to see.
Re: Brown deposits on pool bottom
That's it, when your pool water starts to look that aqua blue/green milky look, you're finally killing it off, another 3 days of filtering with the DE and you should be clean.
PIAlgae is what it SHOULD be called!
Re: Brown deposits on pool bottom
Quote:
Originally Posted by RjBeals
I've had my cl levels at about 30 for 3 days now. pump on 24 hours/day.
Pool is definately clearing up.
An FC of 30 with a CYA of 40 (that you mentioned in an earlier post) is a disinfecting chlorine (HOCl) level of around 1.3 ppm (an FC of 25 is an HOCl level of around 0.8 ppm) so it looks like we are narrowing down the amount of chlorine needed to kill this stuff to be a minimum of at least the column of 1 ppm in this table. If others have this problem with different levels of CYA (especially higher), then we can confirm this and eventually update Ben's Best Guess CYA chart to have at least two shock columns -- one for plain green algae (probably a 0.3 ppm level) and another for this mustard/yellow algae (probably a 1 ppm level). That leaves black algae where others have written about rubbing Tri-Chlor pucks on the algae, but I'm not sure about what overall pool chlorine levels are used at the same time to be effective.
Thank you all for keeping track of your chlorine (FC) and CYA levels during your battles with this algae. I know that the chemistry of what's going on is the last thing to enter your minds:eek:, but this information will ultimately help others.
Richard
Re: Brown deposits on pool bottom
OK, looks like were getting some good analysis going here. I'm not arguing that is not algae, I just think it's stil questionable. Maybe what I had/have is not the same thing. Does anyone know of a type of algae that just settles rather than attach? This is very interesting, maybe we are on to ta new strain???
Wayne
Re: Brown deposits on pool bottom
I have this same thing, started about 3 weeks ago. i thought at first it was from the dog getting into the pool. just put 3 big walmart ultra bottles in pool is about 12k gal. and have 3 more in the car. I vac the bottom sun and it was back tue. so i will keep the fc up about 20 for a few days and vac again sun and backwash.
Re: Brown deposits on pool bottom
Hello everyone!:)
I've been tring to find out what this stuff is myself!:confused: I had to drain and refill my pool about 2 weeks ago so the installers could add some more sand under my liner due to settling. I drained it down to about 2" then it rained the next day.
We got 3" of rain which sat in the pool for another day till the installers came to do the repair. Anyway, I started refilling the pool after they finished.
Once full I added 4lbs. of CYA, and 2GALS of pool store chlorine approx 6%.
I checked the CL. level the next day and it was 1.0 PPM so I added more to bring the level to 4 PPM which is where I wanted it. It held there for about 1 week then this stuff showed up.:( First I hand vacuumed and it came back a little at first then it got worse till it covered most of the bottom and I've been adding about 1/2 GAL of chlorine daily to keep the level at 3 PPM. Then I PANICKED.:eek: I went to the pool store ( Pinch-A-Penny) and let them sell me some Super Green Algicide.:o I dosed the pool with 4oz. as per directions.
and let it work for 24 hrs. then vacuum to waste buy hand. Looked real good just a little cloudy. This was yesterday, This morning I added 3/4 GAL of chlorine and went to work. I just got home and checked and I think it's back just a very little on the bottom so I have the auto-cleaner running now.
My numbers are CL 3.0
FREE CL 4.0
PH 7.4
CYA 40
COM CL 0.0
TO ALK 125
My pool is a 10,000 GAL Above Ground w/ a Clearwater 2600 sand filter What can I do? Help.