Metal staining- not sure where it came from and what to do

[plucky71]

I have metal stains all around the pool. It can mostly be seen when the water level lowers a bit. It is from the waterline down about 18". I am on city water and I don't think we have metals in the water. Before I got the pool working this year, it had been sitting for four years unused. When I started up the system this year, I did run the water through the heater for about one week. The heater does have a slow leak so I ended up taking it out of the loop.

So if it is from the heater and not water supply, what should I do? I don't want to have to use sequestrates for now on if I don't have to. Would I have to remove the water and replace? Can I try the AA treatment and then just see what happens.

I tested the stains with vit c and it did remove/lighten it.

Also, how can I test our water supply for metals? Maybe the water dept. can tell me?

 

[PoolGuyNJ]

Since Vitamin C worked, I would get an Iron Test Kit to test the fill water and pool water.

You may not have a lot of choice WRT using a sequesterant.

What heater was there?

Scott

 

[Melt In The Sun]

If you contact your water provider, they are required by law to have a current (yearly if not more often) water quality report. That will have the information you need.

 

[PoolGuyNJ]

Melt, often iron in the water is localized to the leg off the main. Hydrants and old mains are usually the culprits. The water report you are referring to is from the source or after the treatment center.

Scott

 

[bk406]

Melt, often iron in the water is localized to the leg off the main. Hydrants and old mains are usually the culprits. The water report you are referring to is from the source or after the treatment center.

Scott

Not in all cases. My water has around 1.5 ppm iron in the summer from a secondery well the town uses. The iron levels are in the yearly report. So...it may be worth checking out.

 

[Melt In The Sun]

For what it's worth, some municipalities have reports for different hydrants in the system.

 

[Darkside of the Pool]

What color are the stains?
What is your pH?
Is it possible your pH had dropped very low while the pool was unused?
Do you, or the previous owner, uses (used) Copper Sulphate, Nature2, Copper-Based Algaecides, Mineral Ionizers or something similar?

Some heaters, usually the older ones, have copper elements inside. With a very low pH, often caused by Trichor Tablets and notoriously few tests done during the year, there could be a large scale corrosion inside your heater causing your water to hold a great deal of copper.

Simply answering those questions might save your heater and answer your question.

[Edit] Such corrosion could be the cause of your leak. [/End Edit]

 

[plucky71]

I'm sorry I have taken so long to answer. I have been away from my computer and then I was gathering information to answer the above questions.

I have not yet tested the water for iron, but I plan on getting a test kit so that I can do it.

I'm planning on ordering the ascorbic acid so that I can do the treatment prior to winterizing the pool this fall.

Color of stains- I would say they are yellowish/brown and that the waterline stain may be a little more orange. There is not much color to it so it is very difficult to say. Maybe it is a "tea" color? There are also some darker stains that are spread out throughout the bottom of the pool. They are almost black in color. Some of those are spider web like. Those also were treatable with the vitamin C test.

What is your pH? It is 7.7
Is it possible your pH had dropped very low while the pool was unused? Here are my numbers from the pool store when I first took a sample in on 5/11/10:
Saturation index -1.9
tds 50
cya 0
tot. chl 0.3
free chl 0.3
ph 7
ta 25
th 50
copper 0
iron 0
manganese no

Do you, or the previous owner, uses (used) Copper Sulphate, Nature2, Copper-Based Algaecides, Mineral Ionizers or something similar? NO


The heater that was hooked into the system earlier this year is a Raypak model rp2100 digital.

Thank you all for your thoughts on the subject. I will let you know what I find out with an iron test. Please let me know if the information and pictures above give you any other answers or ideas.

 

[plucky71]

So I am now debating if I really need to test my water for iron. The city states that the source water test indicates iron levels are undetectable. To get my water tested through a local company is costly. The water test results from this spring were from the stagnant pool water before I pushed any water through the heater.

I'm also considering waiting to do the AA treatment until spring.

I don't know what to do?

 

[frustratedpoolmom]

What are your current test results? How long were the TA and hardness levels that low?

I would wait until spring to do the AA treatment. Open in late April while the water temps are cool and do the AA treatment then. If it responded to Vit C then why wait for an iron test, ya know? Using sequesterant and then maintaining the recommended levels for fiberglass and you should be ok. If the PH/TA and hardness levels were that low for an extended period I would suspect the heater, but are you saying the heater was only installed this year?

 

[plucky71]

What are your current test results? How long were the TA and hardness levels that low?

I would wait until spring to do the AA treatment. Open in late April while the water temps are cool and do the AA treatment then. If it responded to Vit C then why wait for an iron test, ya know? Using sequesterant and then maintaining the recommended levels for fiberglass and you should be ok. If the PH/TA and hardness levels were that low for an extended period I would suspect the heater, but are you saying the heater was only installed this year?

Thanks for the reply. The heater is the original heater to the system. So it is 13-15 years old. The pool has not been used for 3-4 years. So the PH/TA levels are an unknown amount of time. I am new to owning this house, so I don't know a complete history on the pool. I started working on the pool this spring, and the numbers I posted above are from when I first started. Those numbers are from before I replaced the pump. When I did replace the pump I found out the heater was leaking. The system was never winterized so the pump housing cracked and I suspect the heat exchanger in the heater also cracked. So I did run water through the pump for about one week and then I removed the heater from the loop.

So I probably will wait until spring for AA treatment. I did order the AA yesterday. If it works, I would rather not have to keep using sequestrates forever. If my water supply is good (no iron) I would rather drain and fill at that time. I guess I'll do the treatment and go from there.

Thanks again for helping me think/work through this. If anyone else has any thoughts on the subject please feel free to chime in.

 

[frustratedpoolmom]

Then ya I'd suspect the heater as the source too (happened in my own pool) I would wait until spring. If your water supply is good after all then eventually thru water replacement your level will drop and you won't need sequesterants on a regular basis.

 

[Darkside of the Pool]

Been long to reply too, sorry about that.

With a TA that low, you can be sure your PH (if tested with Red Phenol) is WAY lower than 7. Combined with a low TH, your water became corrosive, which very well have caused both a leak and your water to be laden with copper (which would again be fitting, since it has 12-15 years old).

However, I must admit my knowledge on what to do about it is lacking. I don't know what could be the effects of winterizing with those stains... will they get harder to remove? My suggestion will always be ''Better safe than sorry.'' but I truly wished someone more knowledgeable would answer this one: My belief might be tainted by the industry.

This comes with another detail. Do not trust only the iron test. If you're heater is the cause, what you need is a copper test. And the reading should be fairly high. Having your heater checked might reveal large scale corrosion: if it is the case you have the missing part of this puzzle.

I hope that helped.

 

[plucky71]

Thanks!