Black in Pool Water – What’s it From and How Can I Get Rid of It?

Water colour dis-figurations are a common problem and headache for pool owners. Sometimes, we see that there’s black in pool water, but have a difficult time tracking down information on what causes it and how we can clear it up. This is because it’s not as common of a problem as say, green or cloudy water. However, that doesn’t mean it’s not as bad. We’d all like crystal clear water, so when it’s colour looks a little off we have to worry about staining and so on.

Black in pool water is generally caused by a high level of manganese. Most pool colour dis-figurations are actually the result of oxidized metals in the water. These colour changes generally appear when the pool is initially filled or after a shock treatment. This is because if the pool contains metals all ready a shock treatment will oxidize them which makes them easier to see.

For black in pool water, here is the standard way of treating the problem.

First, you need to adjust the pH and alkalinity levels to what’s within normal range for your pool.

Next, we need to add a sequestering agent. These are chemicals that combine with the metals in the pool, bringing them to the surface and not allowing the metals to fall to the bottom. This prevents staining during the treatment. Run your pool filter while adding the sequestering agent and leave it running.

Let the filter do its job for about 12 hours. At this point we’ll want to shock treat the pool. After some more time has gone by, retest the pH and alkalinity levels. If the problem hasn’t cleared up, try the procedures again. Sometimes it can be difficult to clear up right away especially if the problem has been around for awhile.

Preventative measures are always the best way when dealing with black in pool water or any other pool issues. This can be hard to do thanks to pool “experts” trying to get the most money out of you as they make you buy this product, or that chemical.