HELP! Light isn't working and I can't figure it out.


New member
Hey guys. Just picked up a used biocube 29 a few days ago. The actinic light would kind of flicker when turned on, then it would be just fine. Over the last two days it has gotten worse to the point I might have to try to turn it on two or three times before it would stay on. Then today flipped it on, it went out, and won't come back on. I figured the easiest way to test if it was the bulb would be to stick the 10k daylight bulb in its place as I know it works. Did this, and nothing. Also stuck the actinic in the daylight slot and nothing. So is it the bulb AND something else as well?


New member
You need to diagnose it further by removing it and looking over all the connections inside the fixture first and foremost. You never know what could have happened to it and it could be a fire hazard sitting there if it was once submerged or has gotten saltwater inside the guts of it.

I believe they have a remote ballast like the Jbj nano's so make sure there isn't a fuse or reset button on it. If your handy with a multi meter you can trace the power throughout the unit to see where it's failing. Fwiw many years ago I had to replace the ballast on my jbj and it was fairly simple to do and only cost like $20 once I sourced the ballast inside the enclosure.