I agree about the price Grant,but at $300 plus shipping($140),considering it went for $3000 new it was worth it.As far as the water taking long to heat,I fill it with hot water from my hot water PW'er,so starting out at 200 degrees the heating element has a jump start,and the tank is double walled insulated so it holds the heat well with the double walled insulated tight fitting top.As far as the waste water .the tank is mobile so I roll it out of the box truck,down the aluminum ramp and set it up outside.I either run it off my generator(10,000watts) or I plug it in at the restaurant,and when the filters are done soaking I empty the tank by opening the ball valve with an attached 2" hose and empty it into the grease trap,or into the drain in the mop sink(then flush the drain with hot water).
I have seen a diagram someone took old oil tanks and added gas burners to the bottom,to make a stationary filter tank for a filter exchange program.I dont see why you could not do that on a smaller scale with a stainless steel industrial tank,some casters,and a propane gas burner setup underneath(with a thermostat temp control,and regulator). of course you would set the tank set up outside,and have someone who works on gas equipment set up the gas burner.If you look under "stainless tank" on ebay there are always all different size industrial stainless tanks for sale from all different types of industrial applications that people salvage and sell on ebay.Some of them are pricy,but some you can pick up cheap.The dipaway filter tank I bought was under restaurant equipment,but for $3000 (new)there really is not much to it.It is just a rectangular tank with a tight fitting lid,a heating element under a grid in the bottom of the tank,casters on the bottom four corners and a ball valve on the bottom.Oh yeah,I forgot an NSF sticker on it which lets them charge all that money for it!
Josh- when they are done soaking,I take the lid off,drain the water out,and leave the ball valve open and the drain hose is left wherever I am draining the wash water(grease trap or mop sink) ,I take all the filters out and place them on the lid which is turned upside down on the ground and put them back in the tank one at a time and pressure wash each one in the tank and the wash water is contained and sent to the drain.