Algae or something else?

[consig10]

Just bought a house with a pool and there are yellowish brown "stains" on the bottom. After 2 weeks of initially starting to take care of the pool, the water is balanced. When first tested, the chlorine level was 0. Water was clear. Added shock, algae (or whatever) disappeared. Stains reappeared after 2-3 days. Have some sort of "frog" chemical system. Water is crystal clear just these spots are a problem.

Attached two photos of the spots. Any advice or help would be appreciated!

 

[supertune]

Hi consig10 and welcome to TFP!
I don't know anything about the FROG system, but what I have heard in this forum is not to use them. I'm thinking it might be a copper based system?

Your # 1 goal is to learn about what method of water chemistry we use here.
Start by reading through the Pool School link at the top of the page.
http://www.troublefreepool.com/pool-school/

Order a FAS-DPD test kit to test pool water. (my recommendation is the TF-100 kit, hands down the best tool in my toolbox!) Get one here...
http://tftestkits.net/splash-page.html

Follow these instruction from here with your pool water test results...
http://www.troublefreepool.com/what-we-need-to-know-to-answer-your-questions-t10341.html
This is what I have done and now I don't have any problems with my pool now!
It's always perfect and SCREAMING for us to come swimming every minute!

Chuck

 

[consig10]

The plan for next year is to get rid of that system and start utilizing this website...they left some chemicals...plus I live in Ohio, we have only a month of swimming weather yet before I close it down. Just wanted to try to take care of these stains before closing if I can.

If that is a copper based system, could the stains be copper? Just wondering.

 

[duraleigh]

Get a tri-chlor puck and hold onto the stains for a minute or two....if they lighten or disappear, they are organic and you need to up you FC level. I can't tell you by how much because we would need to know your CYA level, pH, CH, TA, and FC first. Can you post those?

 

[chem geek]

I wouldn't use a Trichlor puck if this is a vinyl pool (it says it's above-ground so I presume it's a vinyl pool). If it doesn't brush off, you can see if a crushed Vitamin C tablet put on the stain lightens up. Otherwise, shocking with chlorine might lighten it or regular chlorine levels may lighten it over time.

 

[duraleigh]

I overlooked the vinyl liner....tri-chlor puck is not the right thing to do. As Richard said, see if it's a metal stain by using vitamin C. If it's not metal, then you will know it's organic.

 

[frustratedpoolmom]

The stains are there (and they are probably organic) because of the frog system. Exactly how I got started here and what led me to TFP in the first place. The manufacturer of the Frog recommends you maintain the FC at .5-1 without any correlation to the CYA level. As a result you end up with organic staining which fades at shock level but reappears when FC drops to "normal" levels. If you maintain the proper FC level (refer to the CYA chart) and maintain it there for a few weeks - the stains will fade and if you maintain it there permanently they won't ever return. My fains faded permanently after 2 months of the BBB method and they have never returned in 5 summers - thanks to TFP. (The pool store told me I had black algae or a fungus under the liner and my only solution was to replace the liner. The liner is still there and that was in 2007. So there ya go.