culprits green-tinged hot tub water

At Dolphin Pools & Spas, we’re proud to offer not only a wide range of new swimming pool options, but also new hot tub choices as well. We’re a licensed local dealer for Bullfrog Spas, a top name in luxury spas and hot tubs around the country, and we offer all their latest designs and jet technologies.

We’ll also offer several vital areas of expertise for the care and upkeep of your new hot tub. One of the more common minor maintenance areas here takes place when your tub water turns a strange color – the most frequently-seen color here is green, which can result from a few different potential causes. If you’ve noticed green tints in your hot tub water recently, here are some potential sources to check for.

High Mineral Content

The single most common cause of green water in your hot tub or spa is a high quantity of minerals present. This may take place for a variety of reasons, including simple mineral saturation from wells or your local municipal water supply system. In many cases, the green tint will appear just after you’ve shocked the tub – the oxidization reacts with copper present, creating the color change.

In many cases, you can prevent high mineral content by using metal removal products that will get rid of copper and other stain-causing metals in your tub. There are several products out there that can be applied regularly, and then supplemented with a non-chlorine shock to keep your water clean and healthy. In addition, the filter and skimmer can receive some extra attention.

Low pH Levels

In other cases, low pH levels might be the cause of a green tint in your water. Not only that, but low pH also risks bacteria growth in the water, plus an acidic erosion of plastic or metal components.

Luckily, testing for pH levels is very easy. You can purchase simple pH test strips at any home improvement store, then find your Total Alkalinity level and determine if it’s too high or too low. You can adjust this and regulate the pH levels.

Low Sanitizer Content or Shock Frequency

A particularly common cause of green water for those who only use their hot tub or spa sparingly is improper sanitizer levels. In other related cases, the sanitizer levels might be just fine, but you aren’t shocking the water often enough for the sanitizer to do its job properly.

Generally speaking, you should be shocking the spa at least once a week, or potentially after each use even. If you’re concerned low sanitizer levels are causing your green water, you can also buy specific tests for sanitizer quantity and then adjust if your levels are too high.


Finally, while many people often think their green water is due to algae presence, this is actually pretty rare. As long as you’re using a proper cover, you’ll never deal with algae – it requires sunlight to thrive, and will only spread if the cover is removed or left off for long periods. In addition, sanitizer levels have to be low and the filter cartridge may not have been changed for some period of time. In rare cases where algae is actually the issue, contact our pros about how to treat it.

For more on the possible causes of green tints in your hot tub water, or to learn about any of our new hot tubs or our swimming pool services, speak to the staff at Dolphin Pools & Spas today.