Â· Modern Use. Today, basalt is used to a lot of things. Most common use of. is as aggregates. Basalts that are crushed are used for construction purposes, like asphalt paving, concrete aggregate and rock filtering agents. Basalts are added as aggregates to increase strength to concrete. Modern Use. Today, basalt is used to a lot of things. Most common use of. is as aggregates. Basalts that are crushed are used for construction purposes, like asphalt paving, concrete aggregate and rock filtering agents. Basalts are added as aggregates to increase strength to concrete.
Typical filtration cycles are four hours, twice per day (for hot tubs operating a single or two speed pump). Reducing the cycles to 3 hours twice per day will save water pumping energy. These circulation times should be set for off-peak hours. (Some hot tubs have small, low wattage circulating pumps that run 24 hours a day. Typically these draw less energy than a 100 watt light bulb.
Litres of water divided by the average number of people in the spa for a 20 minute session each day divided by 12. That gives you the number of days between each water change. For a typical family spa that formula should be telling you to drain and refill your hot tub about every three months.