The tanks have a built in drain nipple to receive the primary and secondary standpipes. This system was old and set up for flow through so leaks were to likely to be used in recirc. From the bottom a 4"x2" Fernco was attached to the fiberglass nipple. A two inch pipe 8 inches long with a couple glued to the internal side was passed through the fernco.
The foam expanded and made the standpipe couple fitting very sturdy. The small sump around the couple is to receive the original aluminum secondary standpipe that allows for bottom collection. The couple was set to be even with the bottom of the tank and Great Stuff expanding foam was used to fill the space between the 2" pipe and the inside of the fiberglass nipple. The couple even with the floor is the new receptacle for the 2 inch primary standpipe.
The primary standpipe is 28 inches tall with the top 3 inches slotted to retain the fish to a depth of 24 inches.
The secondary standpipe is aluminum and in need of a new powder coating. This stand pipe is installed for bottom collection of water and solids for heavy loaded tanks.
A close up of the secondary standpipe base showing the intake holes even with the floor of the tank. The water will be flown tangentially creating a circular flow bringing the solids to the center for better solids capture at lower flows.
See the whole project here.
See the whole project here.
