BRT LArval rearing system

Craig Anderson

Reefing newb
BRT LArval rearing system
I have finished my larval system. It has a BRT (Black round tub) larval tank, hooked to a 50 gal sump and skimmer. The BRT has a central standpipe with a bubble ring on the bottom. This keeps the larva suspended in a kreisel type current and off the wall. The central standpipe can be adjusted for height to control larval volume. The central filter is removable for cleaning and is wrapped in 250 micron cloth. The water delivery to the BRT from the sump is designed to be very slow. I emerges just below the bubble ring and is part of the up flow. My goal is to cycle the larval water every 1-2 days. This a drip at best. The BRT drain is 1/4 tubing and it terminates in the sump above water so I can count the drops to estimate the turnover rate. Both tanks require heaters because of the extremely slow turnover rate.
I am now waiting to establish the next Neon Goby fry date and I will fill the larval system from the brood stock system and see how it goes.

I have been looking at other BRT systems to see how they place the larval heater. Many place it on the bottom, but complain about larval deaths near it. Other strive to place it near an air stone to keep water moving by it. Some have mounted it on their standpipe. I am going to try another approach. My tub is being wrapped in two 120 volt heating pads. They will be controlled by a Ranco temperature controller. I will post a picture when I get it covered.
I had goby fry in my larval snagger this morning meaning, they hatched last night. The last time was Feb 13th or 17 days. That means in 17 days I should have another hatch. The green water is up and running and I get a million type s rotifers tomorrow. I will have the larval system up and running for the next hatch. We will see what happens.
I have now completed the BRT and its water testing. I tried to keep the inside of the tub free of any obstructions. One way to do that was to heat the outside of the tub. It is wrapped in 2 ea. 12 x 24 inch heating pads. Both pads are plugged into a Ranco temperature controller. It keeps the tub temperature very stable. But with the pads being wrapped in a sheet for insulation, and the wires hanging everywhere, it reminded me of a space capsule just before launch.