rust colored staining on liner. steps and other surfaces

[jtodd8]

I have a 16' X 40' inground pool. I do not have a heater. I have a chlormatic II salt generator. The problem I have is that my salt cell stopped working and I purchased a new one to the tune of $700 and the rust staining started as soon as I turned it on with in just a few hours. I then returned to the dealer that I purchased it from and was told that the cell was working fine. I then bought ascorbic acid Vitiman C and added it to the pool which cleared up the staining immediately only to return the next day. I had my water tested and other than calcium being a little low water was fine, I had the pool tested for phosphates iron and copper all of which were all negative. I have treated the pool for staining 3 times now but staining continues to return, water even smells and taste like rust. The dealer said that the salt generator could not cause this problem. I have turned the generator off and ran just chlorine tablets for a week, I still get staining but not near as severe as with generator on. I was starting to get lite staining but when I turned the generator back on the deep staining returned almost immediately. I don't know what to do at this point can someone out there give me some ideas to try.

 

[Guest]

Have you added a metal sequesterant to your pool? You need to. All the ascorbic acid does is remove the stains. The sequesterant is what keeps them from returning.

 

[jtodd8]

if my water is testing negative for metals will this even help to add a sequesterant?

 

[Guest]

If you have stains that disappeared when you treated them with ascorbic acid then you have metals in your pool! I wouild suspect that you have iron in your water. The reason the stains appeared when you put the new cell in is because you now had enough chlorine in the water to oxidize it and have it deposit as stain. Ascorbic acid is only half the treatment. It MUSt be used with a seqesterant to keep the metals from being reoxidized by the chlorine in the water. Keep your pH NO HIGHER than 7.6 at all times (try lowering your TA to about 70-90 ppm, this will help) and make sure you keep a maintenance dose of sequesterant in the water to keep the staining from reappearing. Just because the water tests negative for metals doesn't mean they aren't there. The fact that your staining was removed by ascorbic acid proves that they are!

Right now you need to put in an initial dose of seqesterant (for most products that would be 1 qt. per 10000 gallons) and use a maintenance dose weekly to montly to keep the stains from reappearing. I have found the HEDP based ones(Metal Magic, Jack's Magic) to be more effective than the EDTA based ones (Natural Chemistry).

 

[jtodd8]

staining

Thank you for your help I have added more acid and the metal free. I was told to wait 48 hrs then completely take apart my DE filter and clean. I'll let you know if this solves my problem. Thank you again :-D