Algae or Stain

ches0529

0
Bronze Supporter
Mar 25, 2017
11
TEXAS
Pool Size
8400
Surface
Vinyl
Chlorine
Liquid Chlorine
Hello all,

I have been a pool owner for 8 years or so now. I have been using the trouble free pool method for 6 of those 8 years. For 6 years it has been simple and have had no problems thanks to all the info found on this forum. Thank you all!

long story short my family had an emergency and we had to be out of town for a littler over aweek. Due to the emergency my pool was the last thing on my mind. I get home and find the pool still clear. I open the pump lid to clean out the basket and the locking ears break off. Great! It took me a couple days and a few phone calls but o finally find a replacement. It took over a week to arrive. So at this point I’m at 3 weeks with no filter and no bleach. 3 days before the lid arrives I come home from work and the pool water is a light green. At this point I just try not to let the green water bother me too much. The next day I come home from work and the water is as clear as it was before all this. That made me scratch my head. Water stayed clear never turning back green. Pump lid comes in. I get the pump going and start checking numbers. Here are my numbers from the original test:

FC- 0
CC- .5
PH - 6.5
TA - 30
CYA - 78

CYA was high due to me having to use some pucks because liquid chlorine has been impossible to find in my area along with plain bleach. I have since been able to find plenty of bleach.

I knew I had to slam so I adjusted the PH to 7.0 adjusted the TA to 70 and retested the PH which had now went up to 7.3. Water was still clear but I had what I thought was algae on the bottom of the pool. I vacuum the pool and brush the walls and floor. What I thought was algae did not come up or move. I bring the chlorine level up to slam at 31ppm. I have kept it there for the last 60 hours. I am losing 4 ppm on the over night test. This morning I had still lost 4 ppm but my CC was at 0.

The algae/stain is still on the bottom and does not appear to be getting better or worse. I tried laying a puck on a spot for a few minutes and nothing. I tried the Vitamin C pill and again nothing. Could the PH being so low have stained the liner? I will try and add some pics shortly. Any info or advice will be very appreciated.
 
Tried to take some pics but the sun is so bright the pictures do not show the spots. I will try later at dusk to see if that will work. The spots are a very light brown and seem to follow the flow of the water. My pool is in full sun so no shaded area to speak of.
 
We know low pH for an extended time can effect a vinyl liner. But normally it is wrinkling. Have you gotten in the pool and see if there is a different feel to the line in that area?

Copper can be another stain inducing metal. You do not show a heater. But low pH can dissolve a copper heat exchanger.
 
Thank you for the reply. I do not have a pool heater. Just the pump and sand filter.
I have not gotten completely in the pool. Got on the ladder enough to test the area with a puck and the vitamin c pill. I’m assuming being at slam level for over 60 hours it is safe to enter? Surely anything harmful would be dead by now.
 
As long as the FC is at or below SLAM level, and you can see the bottom of the pool, it is safe to swim.
 
I got in the pool this afternoon. No difference in feel from the stained areas or the non stained areas. I tried scrubbing the areas with a wash rag, and a magic eraser with absolutely zero success. Being completely in the pool I decided to again try the Vitamin C pill. Actually being under the water and rubbing the pill on the stained spots worked like a charm. Every place I rubbed the Vitamin C the liner looks brand new. Surprisingly putting the pill between my toes this morning just didn’t do the trick 🤷🏻‍♂️
So now my question is what happened and why? I have had a pool for 8 years. I have never had this happen. This is actually my first ever slam other than closing the pool. I am OCD with my testing and balancing of the water. I have never had an issue with staining although I have never had the water tested for metals. Is it a combination of the TA and PH getting so low that caused the staining? Was it the algae? Do the trichlor tabs that I used add metals to the water?
 
Vitamin C removing the stain typically means iron. Do you have iron staining in your home?
What trichlor do you use? Anything with 'Blue' in the name typically means copper.
 
No iron staining in the home. I used pool time 3-in-1 chlorinating tabs. Trichloro-s-triazinetrione 99.0% other ingredients 1.0% I can’t find any other ingredient listed. I used them for a week in June while I was on vacation. I used them for 2 weeks in July untill I was able to find plain bleach in my area. I used it enough to raise my CYA from 40 to 80.
 
I think those tablets should have been fine.

Get a thin sock and put a handful of vitamin c tablets in it. Crush them up a bit. Set it on the stain. Should not have to rub it. If iron, should swiftly lift the stain.
 
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I passed the OCLT this morning. 👍🏻 I tried the Vitamin C pills in a sock. It worked as you said. So I guess it is Iron.
I still don’t understand why now. Only thing that has changed is me not being able to stay on top of the pool maintenance.
I guess I now need to do some reading up on how to correct this issue. I’m assuming removing the stains will only last so long and they will return unless I treat the water somehow?
 
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Hey Ches !!! I just wanted to add my similar goof for future knowledge. My SWG died and I had no clue I could add liquid chlorine while waiting for the replacement. Without a pump you can brush or even swim it around. Such an easy work around to save getting a swamp, be it equipment failure or an extended power outage.
 
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