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SWIMMING POOLS
MINERAL PROBLEMS
White Coating On Inside Of Skimmer Pipes (12/21/98)
Corroded Heater / Green Pool (8/3/98)
Iron In Pool w/ Ozonator (7/15/98)
Copper Problem? (5/19/98)
Chemistry Project - Removal Of Iron In Pool (5/1/98)
Using Well Water In The Pool (4/28/98)
Iron Stains In Pool (4/16/98)
Green Hair / Ionizer (4/13/98)
Iron In Pool Water (4/13/98)
White Coating On Inside Of Skimmer Pipes (12/21/98)
Q:
We have an indoor pool which is eleven years old. We have an ozonator and add chlorine by putting tablets in the skimmer baskets. Both skimmers have stopped working and no amount of blowing them out seems to help. In one you can see a thick white bubbly coating on the inside of the pipe. The coating is very hard and we have not been able to remove a piece. Any suggestions?
D.G. - St. Albans, VT
A:
A white deposit could be calcium carbonate. This could be caused by high levels of calcium hardness. Were you using calcium hypochlorite tablets???? Have you ever had the calcium tested???? If the water source hard????
Lowering the pH onto the acid side will dissolve calcium, but will lead to corrosive conditions. From your description I doubt if there is a quick chemical fix. Have you considered a replacement of some pipe if possible????
Tablets in the skimmer is not the best method of chlorinating a pool. You should consider using an in-line feeder or floating dispenser and a suitable product.
Good luck.
Sincerely,
Alan
Corroded Heater / Green Pool (8/3/98)
Q:
The total alkalinity in my pool is fine. I've possibly added too much sodium bicarb. When I put liquid chlorine in the pool to raise the ph, the pool turns green. The corrosive ph had ruined my pool heater in two years. Any suggestions? I have used soda ash, and bicarb. I don't want to overdo the chemicals.
L.C. - New Hartford, NY
A:
When you ruined the heater by allowing the water to become corrosive for an extended period it resulted in corrosion of the copper in the heater. The green you are seeing is from the copper and is sensitive to pH changes. You must treat this the appropriate chemicals or it will result in a myriad of problems: staining, discoloration, etc.
It would be helpful to know the extent of the copper problem. Try and find a local pool professional that can perform a copper test. Based on 10,000 gallons add 1 quart of SUN Mineral Control for each 0.5 PPM of copper found. This provides an excess as a safeguard.
Until this is done, avoid raising the pH or adding chlorine. After treatment, filter continuously and allow at least one day to completely react with the copper. Do this ASAP.
I hope this information will prove helpful.
Sincerely,
Alan
Iron In Pool w/ Ozonator (7/15/98)
Q:
I'm a new pool owner (2 years) and have had nothing but trouble trying to keep the water clear in my pool. Up here in Alaska our water comes from our own private well and does have iron in it. Adding chlorine just turns the pool brown the more I add the darker it gets. It's impossible to filter out. I haven't been able to "shock" the pool because of this condition.
I'm currently using a friends small spa ozonator and it's worked the best so far in keeping the pool clean but I notice green algae starting to grow now after about 2 weeks. I ordered a bigger ozonator unit but haven't got it yet.
What chemicals or suggestions do you have that can help my ozonator keep the pool clean and remove minerals so that I can shock it properly?
G.G. - Pilot Point, AK
A:
The ozonator will not solve all the problems!!!!!!!!!!
Bring a water sample into a local pool professional for a water analysis. You must determine how much iron is present.
For each 1/2 of a PPM of iron add the recommended dosage of SUN Super Quest. Whenever makeup water is added, add another dose. Do this before adjusting the pH or total alkalinity.
Ozonators are not effective against algae growing on the walls. Once the ozone stream stops, there is little continuing sanitizing action.
It is usually suggested that the water be periodically be treated with non-chlorine shock. Use a Non-Chlorine Shock Treatment, such as SUN Brite to provide a small residual of shock. Test for Free Chlorine. Try using an algaecide such as SUN Algaecide 60 to add a better degree of algae control.
I hope this information will be helpful.
Sincerely,
Alan
Copper Problem? (5/19/98)
Q:
We have too much copper in our pool water. When we put the first shock treatment in, the water went from a dirty green to a brownish red. Other years, we put COP-OUT in the pool but the copper doesn't seem to want to leave. What should we do next?
Pat
A:
Green could be a characteristic color of copper. I wouldn't bet on brown.
Where did the copper come from?
How much is too much?
A chelated copper algaecide is usually not a problem.
If you are using well water, a variety of minerals could be part of the problem.
It is possible that the product you are using has not been added in sufficient quantity. The dosage given on the label is usually based on up to 1 PPM. If there is a higher level, a proportionally higher amount must be used. If well water, double it.
Even if you add sufficient quantity and all vestiges of the problem disappears, it is still possible to test positive for copper. The copper is not actually removed - it is chelated and remains in solution and can be picked up by some testing methods.
Find out how much of what is in the water and you'll be on the right track.
I hope that I have been of assistance.
Sincerely,
Alan
Chemistry Project - Removal Of Iron In Pool (5/1/98)
Q:
Dear Alan, I am a chemistry student at the University Of Wisconsin. I am working on a project for my analytical chemistry class and wanted the opinion of an expert. We know that there is a substantial amount of iron in the pool and a reddish brown precipitate forms. My question is: what in your opinion should we use to remove the precipitate. We have narrowed our choices down to EDTA and a few condensed phosphates. If you could give me some help it would be greatly appreciated.
G.G. - Madison, WI
A:
To control iron in a swimming pool, EDTA would work. Phosphates such as sodium hexametaphosphate would not work satisfactorily in the long term because they will convert to the ortho phosphate form. In addition a chelating agent must form colorless complexes with iron, even in the presence of chlorine, in order to be useful in the swimming pool industry.
FMC Corporation is one of several companies that manufacture a product that is popular in controlling iron in swimming pool water. Dequest 2010 will form a colorless and chlorine stable complex with iron. The trick is to add enough product to react with a high concentration of iron. Most consumer products are formulated to treat up to 1 PPM in 20,000 gallons of water. If you know the iron concentration, you can figure out the dosage. However, well water contains a variety of minerals that will compete for chelating agents.
I hope this information is helpful.
Sincerely,
Alan
Using Well Water In The Pool (4/28/98)
Q:
I would like to know if it would be harmful to use water from my shallow well to keep the pool topped off. The public water in my area is very expensive and if I could use the water from the well it would save me a ton of money. I have a 15K gallon pool and I'm only talking about adding 100+ gallons of well water every other day until our rains start. The well water is not sulphurous or hard, but does have a rain water kind of smell to it. Thank you for your time.
M.W. - Sarasota, FL
A:
Well water can be tricky. Make a sample in your local dealer and have a water analysis performed. See if there is iron present!!!!!!!
If the water tests out reasonably OK, I would proceed as follows. Add Sun Mineral Control at double the dosage rate to the pool before adding make up water. Add water to the pool through the skimmer. Backwash or clean filter after addition of the water.
Good luck.
Sincerely,
Alan
Iron Stains In Pool (4/16/98)
Q:
I have an inground vinyl liner pool. 15X30 5' deep in center 3.5" on each end, approx 13,500 gallons water. This is a Fox Pool.
The pool is starting it's 4th season. I was told by the installer that I needed to run my well water through my skimmer and through the filter to avoid hard water problems. This I did on a regular basis. The end of the second year I started noticing iron deposits on the liner. The start up on year 3, I use some commercial product designed to remove these stains. It didn't work. I followed directions by dechlorinating the water, adding this solution, turning off the filter, using a brush and scrubbing the sidewalls daily for 1 week. Turning the pump on after 2 days and rechlorinating after 1 week.
The stains are located on the sidewalls in the corners. There are none in the bottom of the pool.
I now use a iron removal product and the stains are not increasing in size or changing color. This is my first pool. The installer visited my home and advised me on chemicals needed, what to add when, and also discussed my hard water from my well that I'd be adding to top off my pool. We trucked in water to fill my pool from the local water utility. It was never once mentioned that I would need to add iron treatment for the water, in fact, part of his sales claim was to provide "all the chemicals" for the first year. Iron treatment was not part of them. Now I have stains on a liner that is less than 4 years old that will cost about $1200 to replace.
I have also read where vinyl will actually absorb a stain making it next to impossible to remove.
What do you suggest will remove these stains?
Acid wash has been recommended but my fear is damage to the vinyl liner coatings.
High chlorine levels have also been suggested.
The manufacturer of the vinyl for Fox could not tell me what to use, nor could Fox but did caution me on the use of acid. They cautioned the use but didn't know one way or another if it would hurt anything. The use of acid has been recommended by 3 different vinyl liner pool installers and servicers. They say the iron will come right off with little or no effort.
I look forward to your response. I would like to clean this up when I open my pool soon.
Thank you in advance.
R.B. - Fort Wayne, IN
A:
Adding makeup water through the skimmer is a good idea. It will help remove suspended minerals and should be followed up with a backwash to waste to keep those materials from dissolving in the pool water over time. It will have no effect on the dissolved minerals.
Adding chlorine will not help remove iron stains!!!!!!!!!!!!
Products formulated to treat iron and other minerals can typically treat up to 1 PPM of iron per quart of product in 10,000 gallons of pool water. Using well water can mean very much higher levels and it is likely that sufficient product was never added. As a rule I recommend doubling the quantity added because of the presence of other problem-causing minerals.
Testing for iron will give you insight into the magnitude of the problem. Bear in mind that an iron test will only measure the iron remaining in solution and not include that which has precipitated on the pool surfaces.
There is a regimen that I have found to be successful in removing stains. Take an old sock and add about 1 pound of pH Minus, shut off the filter and drop onto a stained area. After 10-15 minutes there should be a noticeable improvement in the immediate area. If this is the case, then it confirms the problem is mineral staining and the following should be done.
Lower the pH of the pool to 5-6 using muriatic acid or pH Minus. Allow the water to recirculate and retest pH. After pH has been confirmed to be under 6, shut off filter. Use brush occasionally and allow 1-2 days for the acid to dissolve these deposits.
After the stains are dissolved resume filtration and add 1 quart of Sun Mineral Control per 10,000 gallons of pool water FOR EACH 1 PPM OF IRON PRESENT IN THE POOL WATER. This is important to avoid a recurrence of the staining. Adjust pH to 7.2-7.6 using total alkalinity booster instead of pH Plus - this helps avoid locally high pH readings which could cause precipitation.
In the future always add some additional product each spring or with each makeup water addition.
I hope this information will prove helpful.
Sincerely,
Alan
Green Hair / Ionizer (4/13/98)
Q:
We have an ionizer on our pool, my daughters hair turns green. What can I do to prevent this? Is there a hair product we can use?
D.L. - Littlerock, CA
A:
Green hair can be caused by the excessive presence of ionic (unchelated) copper in the water. Certain individual hair types are more susceptible than others.
The ionizer that you are using is a source of ionic copper. If you have a heater, corrosion of the copper heater coil could be another source. If you used drinking water to fill the pool, it is not a likely source of copper.
Have your pool water tested to determine the copper level. If too high, a product such as Sun Mineral Control can help chelate some of the copper and, perhaps, eliminate the problem. Removing all the ionic copper will interfere with the algaecidal action of the ionizer.
In the past, I have recommended Wella Balsam Hair conditioner to help remove the green. Shampoo, apply generously, leave on 10-15 minutes and rinse.
I hope these information will prove helpful.
Sincerely,
Alan
Iron In Pool Water (4/13/98)
Q:
Ok. Here's the deal: I recently filled my pool with water from a well and after adding hypochlorite and a buffer to adjust the pH to about 7, the water became cloudy and a reddish-brown precipitate formed. Do you have any ideas as to what this precipitate may be? I'm guessing that it is some type of iron complex. Thanks.
R.S.
A:
Bingo!!! You probably hit it right on the money. So now what???
Well water is frequently a source of iron depending where you are located. Your water sounds so bad that I suspect that you have, or should have, a water softener for household water.
ASAP have your pool water tested for iron. Backwash the filter to waste. We don't want to dissolve any iron that has been filtered out. A product called Ferritabs usually works well under these circumstances. Follow the directions.
The next day (or immediately if Ferritabs are not available locally), add a quantity of Swim-Free Hydro-Quest based on the iron test. For each 1 PPM of iron add 1 quart of Swim-Free Hydro-Quest for each 10,000 gallons of pool water.
The water should clear within a few days if enough Hydro-Quest has been added. After the water clears you could have some stains. Add some more Hydro-Quest, about 1/2 of original amount, and lower the pH to well below 6.0. Recirculate for a few hours and shut off the filter. If the are any locally stained areas on the bottom, drop some pH Minus on the area. After the stains are removed, raise the pH by adding total alkalinity booster and pH Plus as necessary.
Every time you add make up water, you risk a recurrence. Consider adding softened water. Always add water through the skimmer to filter particles. Add some (1 quart) of Hydro-Quest before adding makeup water.
I am sorry I can't be more specific, but I lack specific details.
Good luck with the problem.
Sincerely,
Alan |
