What could my problem be? Brown splotches and "dust bunnies"

Lil Davy

Member
Jun 2, 2010
17
I'm trying to figure out what my problem is, and now, from reading several posts, I'm wondering if I don't have two problems.

The first problem, which I didn't think was a problem, is that I keep finding these brownish clumps, almost like dust bunnies that I attributed to "gathered dirt", etc. From reading, it sounds like these may be mustard algae, but I'm not sure. I always have the filter running, and the water is crystal clear - and I always have the solar cover on when not in use. Could these clumps be mustard algae? Does anyone have any pics of this?

My second issue that I just discovered yesterday is brown splotches in the pool bottom. They look like stains that are now covering about 10% of the bottom. I tried brushing it and they didn't come off. These splotches weren't there two days ago. I'll have to get the chemical readings when I get back home, but I'm just trying to do some homework to figure out what I am dealing with.

Thanks
 

257WbyMag

TFP Expert
LifeTime Supporter
Feb 23, 2008
5,061
Denton, TX
Welcome to TFP!

Could be clumps of dust and/or dirt on the bottom. There really isn't any way to know if you are having an algae problem until we see your test numbers.

The brown stains that won't brush off may be organic stains or metal stains. Try rubbing one of the spots with a chlorine tablet. If the spot fades, it is organic and chlorine will take care of it. If the spot doesn't change, try rubbing a vitamin C tablet on it. If the spot lightens with a vitamin C tablet, it would be a metal stain.

We need the following test results to start: FC, TC, CH, CYA, pH, and TA.
 

Lil Davy

Member
Jun 2, 2010
17
Thanks. I'll get the test results later today when I get home. I did a quick test last night and the PH was 7.5 and the Chlorine was way low (ZERO). So I shocked it.
 

Lil Davy

Member
Jun 2, 2010
17
BTW - prolly a stupid question, but where do you get a Vitamin C tablet? How big does it need to be?
 

Lil Davy

Member
Jun 2, 2010
17
So I just drop the Vitamin C tablet on the stain on the liner and leave it there? How long should I wait? Same question with the Chlorine puck?
 

frustratedpoolmom

TFP Expert
LifeTime Supporter
In The Industry
May 20, 2007
12,177
SWSuburban Chicago, IL
Vitamin C will have an immediate reaction if it's metal. Iron will vanish almost instantly. Other metals tend to change in appearance.

Trichlor will have a slightly slower response depending on the stain/surface of the pool but is usually pretty quick too (if it's going to work).
 

duraleigh

Admin
Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
31,697
Sebring, Florida
Davy,

I would focus on getting the chlorine correct in your pool. Once you complete that process, I have a feeling the stainng will take care of itself. If not, you can address it then but having your chlorine set and replenished correctly should be job # 1.
 

Lil Davy

Member
Jun 2, 2010
17
OK so last night I put in 2 lbs of shock (Calcium hypochlorite) and I just checked and the spots seem to have disappeared (pheww!!!) SO here are my tests:

pH - 7.4
TA - 150
FC - 1.5
CH - 300
CYA - 0
Total Gallons: 13500

In kind of shocked that the CYA is so low. (I'm running the Frog System) What is needed to raise my CYA?
 

Bama Rambler

Mod Squad
TFP Expert
LifeTime Supporter
Jun 22, 2009
23,044
SouthWest Alabama
I would be very suspiscous of that CYA number if you've been using the Frog system any at all. It uses 1" Trichlor pucks so if it's ran it's added some cyanuric acid.
 

Lil Davy

Member
Jun 2, 2010
17
Bama Rambler said:
I would be very suspiscous of that CYA number if you've been using the Frog system any at all. It uses 1" Trichlor pucks so if it's ran it's added some cyanuric acid.
I agree about the Frog System; however, the pool has only been open for about 10 days plus we just got about 3 inches of rain in the last two days.
 

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