I've not owned or used a genuine Lava
tank, but I have used a cartotank with the same design and principles.


Basically these are uniquely designed end caps made of acrylic or stainless steel. The top cap and mouthpiece are milled together as one piece from a block of acrylic material, so that the
tank can filled/refilled by removing the entire top cap from the tank. The caps are press fit onto the tube portion.
The tubes are generally made of polycarbonate plastic, which is succeptable to the tank-cracking flavors. Some manufacturers offer pyrex or quartz glass replacements.
For myself, they were nothing special from any of my other cartotanks, other than for their unique appearance. They are also on the pricey side.