Mustard Algae or Dust

[southernpool1]

I joined TFP because of a mustard algae problem I had. I followed SLAM and cleared the problem. Water was clearer than I have ever seen it!

Now I'm wondering if I have it again....it's been two or three weeks, and every time I brush the pool clouds of dust or algae come from the bottom and sides of the pool. It is not concentrated on the shady side, and my FC loss is about 2 ppm per day. I have 0.5 CC's almost every day (some days are 0 CC's). I have maintained FC between 3 and 5, and I test and add chlorine daily.

I may just be overly concerned about another outbreak. Will that much dust or pollen cover the bottom of the pool in a couple of day or two?

FC 5
CYA 40
PH 7.5
CC'S .5
CH 275
TA 80

 

[BoDarville]

A couple of things...

1. Is a layer of pollen / dust accumulating on surfaces near the pool such as patio furniture?
2. When you last SLAMed the pool, did you check behind the pool light niches (if applicable)? If not, it's worth doing since that is a favorite hiding spot for algae that can recontaminate the pool surface if it is not eradicated.

I would also suggest upping your chlorine level slightly. At your pool's CYA level, while 3 ppm is the minimum, the target FC level is 5 ppm. I would suggest maintaining FC between 5 and 7 ppm (the high end of your recommended range) and see if you note any improvements.

 

[needsajet]

An OCLT will tell you if there's algae. Pool School - Perform the Overnight FC Loss Test (OCLT)

From my limited experience, the Polaris is good for big stuff, but not so good at vacuuming up dust. You could try your manual vacuum moving very slowly as you cover the bottom. In the evening use your brush to stir it all up and help it get to the filter. A suction pool cleaner is another option. When my pool was new and there was plaster dust, I left my manual vacuum upside down in the deep end to help capture some dust. My filter works best on low speed right after cleaning so it gets charged with fines and doesn't just push them through. My filter works better after it gets dirty, so I avoid backwashing until the pressure is 25% above clean pressure. Adding DE may be something worth trying as well. Pool School - Add DE to a Sand Filter Just a few ideas to ponder, and I hope it clears up for you soon. It takes a while sometimes.

 

[southernpool1]

Our backyard is dusty, but it just surprises me that I would get that much dust over the course of a day...but I am a new pool owner, so I have no reference point.

I haven't performed OCLT since the SLAM, but if I'm only losing 2 FC over a whole sunny day, wouldn't basically be impossible to lose more than 1 over the night?

I did not check behind the light niche though....not sure I would even know how to remove the light. Is it difficult?

I will move the chlorine to 7 tonight.

My filter never got close to 25% over filter pressure, even during the mustard algae bloom. I have only backwashed once since before the outbreak, and that was yesterday, but pressure was never noticeably different. Is this okay?

What is a suction cleaner? Is this like a Kreepy Krauly?

Can I add DE to a sand filter this new? I am just thinking about any warranty issues.

 

[needsajet]

Good comments. I don't know your use and shade situation, but for sure the OCLT will show up an algae or other organic FC extinction issue. Totally agree with upping the FC.

Good chance the light has a couple of screws holding it in and enough spare wire to set it on the coping. For mine I just need to take the screws out and pry the bezel gently with my fingernails, then fingers. Any other algae hidey places? ladders, back of skimmer weir, under coping overhang, etc.?

Kreepy Krawly is one brand/type of suction cleaner, yep. Some people think of those as the diaphragm type. There's also ones with wheels that are quiet and good at vacuuming.

Good to hear that your filter is a bit dirty and running well. I'd probably leave it alone in that case.

The DE gets backwashed out, so if there was any kind of warranty issue, which I haven't heard of, you would backwash before calling for service. Our pool builder recommended it, and he supplied the filter, so he'd have a hard time not backing me up! To my limited knowledge, it won't hurt the filter, done right by TFP methods per the link in pool school.

And glad you got BoDarville watching the thread too. He's an expert and I always defer to the gurus for sure.

 

[southernpool1]

Thanks to all for the help! I conduct OCLT tonight and see what I come up with, and will check the light if it shows over 1 FC loss. I will review the DE instructions also. I haven't considered doing that yet.