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Brown Pool Water

Brown pool water Brown pool water can be alarming for swimming pool owners. Fortunately there are only a few common conditions which can cause the water in your pool to turn brown so all you need to do is identify which of these conditions relates to your pool situation. Before you start adding chemicals to your pool you should evaluate what you did with your pool directly prior to the water turning brown. For example, if you added some chemicals last night and first thing this morning you notice the pool is brown, the chemicals you added are the key to solving your problem. If you did not add anything to the pool recently then this, in and of itself, is a clue. Also note whether there has been any rain or heavy use of the pool recently.


Pool owners tend to get into trouble with their water quality when they react to developing problems before they fully understand what is happening in the water. If the pool looks funny, a pool owner may decide to add chlorine, or acid to adjust the pH, when in reality neither of these are the correct course of action. The first thing that you should do when you notice your pool water deteriorating is to have a full analysis of your water from a local water lab. If you do not have a water lab convenient to you then you should test the water for the following parameters:





This Taylor K-2006 test kit is what I consider to be the minimum home test kit that every pool needs to have. Using off-brand or low quality water testing equipment as your primary method of testing your water is a mistake that many people make. I can not think of many things more important to pool care than being able to measure accurately what is happening in the water.


So many pool owners overlook the most obvious thing...water testing. All of the answers to your problems are in the numbers of your water tests. Nine times out of ten when a pool professional asks a pool owner about their pH or chlorine levels the answer is "they are good". There is no such thing as "good" when it comes to water chemistry variables. Water chemistry in swimming pools is a delicate balance of multiple interacting chemicals maintained in a manufactured sterile environment. To say that your chemical levels are good reveals your lack of understanding of how to maintain a pool. As a pool owner you should embrace the numbers behind the water testing that you do, and part of doing this is using better quality water testing equipment like the Taylor K-2006.


Free chlorine: - The amount of chlorine in the water available to kill bacteria and organic debris

Total chlorine: - The amount of free chlorine and spent chlorine combined

pH: - The measurement of the relationship between acids and bases

Total alkalinity: - The total amount of alkaline materials in the water

Cyanuric acid: - Also called water conditioner or stabilizer, this prevents UV from destroying the chlorine


When your water turns brown in your pool you need to know the levels for each of the parameters listed above, but this alone will not likely solve the problem on its own. There may be a clue in one of them, but more likely you will need to know these numbers in order to proceed with a corrective treatment. The water testing values listed above can be considered "basic chemistry" for every pool. If you keep these numbers in the correct range you can likely avoid 90% of water quality problems with your pool. Something like the water turning brown is outside of day-to-day water chemistry problems so in addition to the values above, if your water turns brown you need to test your water for each of these:





Iron test strips





Copper test strips





Phosphate test strips


Normally test strips are something that I tell pool owners to use with caution. They certainly are very convenient however they are not anywhere near to as accurate as an FAS-DPD test kit. For the basic water chemistry variables you should use the better quality test kits however for the rare occasion that you are testing for iron or copper the test strips should be fine. If you have continuing problems with metals in your water then you might want to pick up a digital water test kit that also tests for iron and copper. Phosphates are somewhat of a wild card when it comes to pool water chemistry. You will get different answers from different sources as to what they do (if anything) and what you should do about them (if anything). If you are having uncommon problems with your water quality then knowing your phosphate levels seems prudent to look for anything abnormally high.


What Causes Pool Water To Turn Brown?

Brown pool water is an uncommon water condition to encounter. Green water and cloudy water are pretty normal situations to have with swimming pools but brown water is much less common. Usually this is a result of either an impurity in the water, or a chemical reaction with an impurity in the water...in either case you need to determine what the impurity is before you will be able to remove it. It is also important to treat the problem as soon you notice it happening. Leaving the water in your pool brown for an extended period of time very likely could result in permanent, or at least difficult to remove, staining of the interior surface.


Opening the pool with a safety cover - Safety covers are becoming very popular with residential pools and eventually will dominate the market. Some safety covers are solid and require a pump to remove any standing water from on top of the cover. More commonly safety covers are made from a mesh material that allows water to pass through the cover while physical debris can not. This particular type of safety cover can often cause brown swimming pool water since leaves and debris on the water will act essentially like a giant tea bag. Tannins from the leaves will be stripped out and will pass through the cover and accumulate in the pool. This results in tea colored brown water in the spring when the pool is opened. If you have just opened your pool for the year, and you have a safety cover, your brown water has been caused by these tannins. To resolve this simply get the pool filtration system up and running and run your pump 24/7 until the water is clear. Most importantly be sure to keep your free chlorine level well above zero as the impurities in the water will deplete your chlorine levels quickly.


Water turned brown after adding chlorine - If you recently added chlorine to your pool and suddenly the water turned brown then this is characteristic of iron in your pool water. Do you use a well to fill your pool? Do you have an old and possibly deteriorating heater that is still connected to the plumbing system? Do you have rusting components visible anywhere in the pool or the pool plumbing system? It is possible to have iron suspended in the water in your pool without you knowing about it. When you shock with chlorine the chlorine oxidizes the iron and causes it to turn brown. If you have iron in your pool then it must be treated and removed or the water will continue to turn brown every time you add more chlorine. It is possible for the iron to stain the interior surface of your pool so be sure to treat your pool for iron right away if your water turned brown after adding chlorine.






This is a pool chemical for disolving iron stains. This product is used first to get all iron in the pool into solution in the water.






This is a chelating agent which you will need in order to get the iron to bunch together so it can be filtered or vacuumed away.






Sparkle Up is used to improve the efficiency of pool filters. This is especially useful for salt filters which are the least effective type of pool filter, but can also be used on cartridge or D.E filters as well to help remove iron from the water faster.






Jack's Magic has a line of stain preventers, stain removers, chelating chemicals and metal sequestering chemicals however it can be confusing as to which of their products you need to use. They have different products for different pools and different treatments. Jack's Magic stain ID kit is for pool owners who are dealing with staining on the surfaces of their pool. This kit takes all of the guesswork out of knowing which products you need to use to first lift the stain and then remove it from the pool.


If you have staining in your pool in addition to brown water then you can try using a vitamin C tablet and rubbing it on the stained area. If the stain reduces then this is confirmation of metals in your pool water. You can also use pH reducer powder in a sock and sit this on top of the stained area, and if the stain reduces this again confirms metal staining. If your pool is not stained but the water is brown then you can use a metal eliminator product to help capture metal that is suspended in the water. For pools with a lot of iron in the water then a chemical treatment that pulls the iron out of solution is best. This will drop the precipitated iron to the floor of the pool where you can vacuum it to waste.






If iron is causing your pool water to turn brown then you should try to identify where it is coming from. For most pools with this problem it will simply be from a rural well water supply that has metals in it. If you have no choice but to use well water then you should consider using a pre-filter which will remove most of the contaminants and metals before they make it into your pool.


If you are using a city water supply or clean water trucks to fill your pool then it is not likely that the iron is coming from those sources. What many pool owners do not realize is that metals can leach into your pool water from deteriorating equipment like pool heaters or metal fittings used as part of the pool plumbing system. If you have any rusting or deteriorating metals in or around your pool then you should remove them immediately before treating the pool for metals.


Filtering out iron - Metals in pool water are tricky to deal with. In order to remove them from the pool you need to get the iron to detach from the pool surfaces and dissolve into the water with a stain inhibitor product. You then need to add a chelating product that will get the iron to bind together into larger particles that can be vacuumed and filtered out of the water. If you have a cartridge filter you will need to rinse off your filters multiple times during the iron removal process as the filters will become blocked quickly. When it comes to dealing with iron, sand filters are better since back washing quickly and easily eliminates iron from the filter.


DIY iron filter - For inground pools it not not very convenient to build your own iron filter however for some above ground pools this will be the best solution available. It is possible to manually filter iron out of pool water simply by forcing the water to pass through a filter such as white cotton socks or white towels. If you are able to change your pool plumbing system such that you force the water to pass through multiple layers of white cotton-like fabric then this will remove quite a bit of iron from the water, especially when used along with a chelating chemical.




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Swimming Pool Steve

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