As an engineer, I have had extensive experience working with the pool hydraulic system and have studied the pneumatic separation (or “explosion”) described. The two-part pool filter system has a bottom and top piece fitted together with a belt-like band. Over the last two decades, there have been many reports of the tops of these pool filters suddenly separating and being blasted off at extremely high speeds. These incidents, in which the tops are known to fly up to 100 feet in the air, are mostly caused by a buildup in air pressure within the filter. Pool filter systems should be cleaned about twice a month by removing the cardboard filters, hosing them down, and fastening them back in. After being cleaned, the tank has to be turned on and pressurized again, which is typically when the “explosions” happen without warning. The separation also tends to occur if the top of the filter does not perfectly sit on the bottom part when the band is applied and secured. The person cleaning the filter may believe that the seal is secure, when actually, they have just set up a time bomb. Though feasible design alternatives which eliminate these explosions exist and have been available for decades, most manufacturers still refuse to recall the dangerous designs. The safer models require more time and effort to clean the filters and might even necessitate special tools or knowledge to clean a pool.