New member, long time pool owner.

DARoss

Member
Jul 18, 2019
6
Sodus Point, NY
A couple of days ago I came across this site and after reading threads relative to my problem, I believe I know the cause. Last night I registered, thanks for the all information posted here!

I'm in over my head, so to speak, on this problem. My pool is a 20x40 vinyl liner, it's 25 years old, cement bottom, galvanized sides. A year and a half ago I had a new liner installed due to leakage of the original installation. That liner did have some staining, in addition to the serious leakage, which the pool guys attributed to possible algae growth on the bottom side. Supposedly they treated the cement.

Fast forward to now, you can see in my photographs that the staining has returned. It's a dark brown/green color which does not scrub off. I do use a copper algicide. The water was drained and refilled within a few months of the liner installation due to some gaps in the cement and stones under the liner. The pool company did a lousy job addressing both, but it is what it is, I should have installed it myself.

I suspect these are copper stains and my only alternative is to drain some water and refill, but I'm uncertain whether I'll ever rid the liner of the stains. Regardless, I have ordered the copper test strips in order to quantify the amount. From the onset of pool ownership I had purchased the Taylor Complete kit and have maintained my pool with care utilizing 3" tablets in an injector setup. My water is always kept balanced.

Wife and I appreciate any assistance and/or advise.

Regards,

DA
 

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Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Welcome to TFP! :wave: So you've had a few headaches early on :hammer: but we'll try to help. As you know now, copper is a no-no in pool water. The staining can be a pain. Hopefully you no longer have such copper products adding to the overall copper level in the water. For those with plaster pools, the best way to get them off is to drain the pool and do a manual acid wash. But in your case (vinyl), you might be better to remove them with a sock full of dry acid held against each stained area for a minute or so. Rub a bit as to not keep isolated for too long. Of course this is a localized treatment process. I'm not so sure there's a better way for vinyl if it's wide-spread. You oculd check with Jack's Magic products. Just pace yourself I suppose. At some point, continue to exchange water to help lower the copper content and consider the use of a good sequestrant to prevent future staining.

ABCs of Pool Water Chemistry
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DARoss

Member
Jul 18, 2019
6
Sodus Point, NY
Thanks for the reply Texas! Not a newbie owner by any means, almost three decades of watching my water. Once I sample the water, that should better define the Cu content and I'll proceed.
 

DARoss

Member
Jul 18, 2019
6
Sodus Point, NY
I was able to test the copper today, it's showing .5ppm, however, the chlorine is high due to shocking. I'm uncertain whether that would affect the reading on the Cu. My staining continues to worsen, the water is balanced and reasonably "new". With all the rain this spring quite a bit was cycled out due to lowering the pool, then adding some due to the hot spell which just ended. Any ideas what to do next? Thank you
 

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
A copper level of 0.3 becomes an issue. The higher it gets the more difficult to manage. Chlorine can skew the testing a bit for metals, but I suspect it's still high based on your description and history of using a copper algaecide. The more water you can exchange the better. You mentioned shocking .... do you have algae? If not, there's no need to shock. SImply keep your water (FC & CYA) balanced as noted on the FC/CYA Chart. Of course if you did suspect algae, the SLAM Process requires a higher FC level and it probably will make the stains appear.

How do you test your water? Do you have a TF-100 or Taylor K-2006C tets kit, and can you post a full set of test results? Maybe we'll see something to help.
 

DARoss

Member
Jul 18, 2019
6
Sodus Point, NY
Thanks again for your reply Texas. The chlorine was a bit high during the test, between the shocking and turning the auto chlorinator up it was in the 5+ range. Total alkalinity and pH were in the normal range, however last night's test showed the PH high, which is very unusual for my pool given the acid added to the chlorine tabs. So moments ago I retested. pH is now 7.2 but total alkalinity is a bit low ie between 40-80 so I will introduce some baking soda. Free Chlorine is now at 3 ppm, I shut down the injector after seeing the high read last night. Stabilizer is ideal. Retested Cu, it's close to the same, between .3 and .5, however, the stains seem to have lightened a bit. My TF100 is out of service, I need some reactive bottles refilled, so I used AquaChek which has compared favorably to my liquid testing over the years. I wonder whether this stuff is biological and might need a really hot shocking. The pool was a bit slippery and some pink algae had formed on the steps and liner, which is not uncommon and cleans off with a brush.
 

DARoss

Member
Jul 18, 2019
6
Sodus Point, NY
The CYA is still low, however, after losing some water and adding several inches to the pool, my Cu is down to almost zero. I have been slamming it, and changed the earth filter medium yesterday. Immediately after my third shock, without the filter running once the dose was well mixed into the water, I saw considerable residue on the pool floor which generally indicates contaminants. At this point, I consider the stains to be a form of algae either from the pool water or from contamination on the bottom side of the new liner. Shock again in a few minutes.