If your pool has a vinyl or fibreglass liner, the calcium hardness level should be between 175 parts per million (ppm) and 225 ppm. If you have a concrete or plaster pool, keep the level between 200 ppm and 275 ppm. If the calcium hardness level in your pool gets too high, the water will be hard. The first indication will likely be a cloudy pool. On the other hand, too-soft water will be corrosive to your pool. The key is keeping calcium levels balanced. Contact us if you need any help.