Algae? Dirt? Dust? Something else?

[gmason86]

Hi all,

I'm very much a firm believer in the TFP methods and follow them religiously. I was away for a week recently, and had some friends add chlorine when they were over checking on the cat, and another friend test in between (he knows how to test properly). It roughly equated to how often I'd test / add anyway, and I had them add a little extra than I usually do, just in case. The main difference is that no brushing / vacuuming (I have one of the robot vacuums) was done while I was away, but the pump was on as often as normal.

What I found when I got home was about two or three thin lines of what looked slightly green/yellow. Unfortunately I don't have pictures. A couple were on the wall near the skimmer (both horizontal) just around where it starts to change from vertical to sloping inwards towards where the main drain is. Another one was near a wrinkle in the shallow end. Both areas receive sun at various times of the day. The lines looked pretty smooth, rather than grainy, and easily brushed away, but I wouldn't say went into any kind of cloud. The pool was dirty (I could tell when brushing) and so the pump run has been upped. I can still see the bottom of the deep end absolutely no problem, but the dirt has made it a little less clear than normal.

Just in case these were any form of algae, I started a SLAM yesterday evening. I did an OCLT, but the results are hard to rely on. First test it was perfect, 0.5 drop at most. For some reason I decided to test again, and it was more like 1.5-2ppm (I can't remember for sure!) drop. The reason I say I can't rely is because of the speed I did them at (How quickly to add R0871? Seeing discrepancies). I can't be sure how quick I did them at night, so I don't know which one was accurate!

Anyway, the levels as of the morning were either at the correct SLAM level or marginally below. My CYA is 30, so the level was 12. I discovered the same line(s), albeit only 1 or 2. I did worry that it was mustard algae, but from what I've read on here so far, it seems the fact it reappeared while levels were so high, and that it isn't dusty when brushed, seem to suggest it likely isn't that.

Anyway, I'm keeping up with the SLAM for now and have just had the robot running. Throughout the entire SLAM process so far (almost 24 hours), there really isn't any signs of dead algae falling to the floor. I'll also do the OCLT again tonight.

Any thoughts?

Thanks!

 

[mknauss]

SLAM is a good idea. Should be quick if not very cloudy.

 

[gmason86]

SLAM is a good idea. Should be quick if not very cloudy.

I'm not sure I'd even say it's cloudy. Maybe slightly hazy, but even that's a stretch and it's only that if the water is moving a lot (e.g. robot doing it's thing and the air bubbles coming out, as well as jets on) or I've just brushed. You can always see the bottom without issue, with it only having that slightly hazy look when at the far end. It's similar to when I open my pool (I have a safety cover), and it's noticeably dirty at first, and then when the filter has been on for a while and is almost crystal clear as it cleans it all, that's where I'd say we're at.

The one other difference between my friends helping to look after it and me was that the solar blanket wasn't on at all, whereas I have it on almost every night and sometimes during the day if we're not using it. My pump usually runs (at varying speeds) from about 5pm for say 11 hours. I'll often throw it on extra at the weekend, but that didn't happen while I was away.

I just popped out to test and top the chlorine levels back up as it's quite sunny today. I did a full brushing while I was at it and where it was clearly generating dirt/dust (it hadn't been vacuumed or brushed in say a week and a half), it wasn't generating anything noticeable this time.

It was just those thin green/yellow lines that had me question things. Maybe a foot or so long at most, and maybe half an inch wide at most (I didn't measure). I'm not sure what they'd be as I don't normally see them, and they obviously reappeared while still at almost SLAM levels. There was a lot of rain while we were away (but I believe levels were always above minimum), and the pollen count seems to be moderate just now.

Any thoughts what they may have been? Any pictures I've seen of algae seem much more noticeable (one time I did have it before I discovered TFP, my water was very noticeably cloudy), and not in a very small number of thin flat lines. I'll definitely continue the SLAM and hopefully done by tomorrow morning (that would be a day and a half). I'll make sure to do my testing slowly at night and in the morning...

 

[mknauss]

Hard to say. Could be algae, dirt, etc. Do an Overnight Chlorine Loss Test if you feel the water is clear. Remember, TFP clear, not pool store clear.

 

[gmason86]

Hard to say. Could be algae, dirt, etc. Do an Overnight Chlorine Loss Test if you feel the water is clear. Remember, TFP clear, not pool store clear.

I'm not sure I remember what pool store clear is anymore - thankfully I've been TFP for long enough now I just know what I'm used to now as clear, and it's not quite that perfect yet.

Thanks for the help - as always, much appreciated.