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.
1 Let the spa run as usual for 24 hours and mark the level of the dropped water. Now power the hot tub off, refill to the original level, and let sit for 24 hours. Note the level of the dropped water.  If the water dropped equal amounts each time, chances are your leak is either in the shell or the jets (vessel leak).