1. Welcome to the shiny new site! Please have a look around and let us know how its working for you. Please note that all returning members will need to reset your passwords to login again. Click on "forgot password" to reset your password. If you still have issues then email us at board@marinecolorado.org Thanks
    Dismiss Notice
Dismiss Notice
Site Upgrade complete! A new version of the forum software has been uploaded. Please let us know if you have any issues. Thanks

T5 lighting modification

Discussion in 'Lighting and Equipment' started by FOURSTARS, Dec 6, 2018.


    FOURSTARS Copepod M.A.S.C Club Member

    I was wondering if you can use at smaller bulb in a T5 unit designed for a higher wattage. I assume if the bulb is less wattage then it would not matter because the bulb is less load then the ballast is rated for?

  2. halmus

    halmus Cuttle Fish Staff Member M.A.S.C Club Member M.A.S.C. B.O.D. M.A.S.C Secretary

    Can you provide some more specifics on what you’re trying to do? T5-HO?

    If it’s T5-HO, for example a 48” fixture will take 48” 54 watt bulbs. You couldn’t possibly use 36” 39 watt without modifying the fixture to move the end caps in.

    From what I’m seeing on the interwebs, undersizing the bulbs for the ballast would result in bad things. For Florescent tubes, I’m reading that the ballast is there to limit the current going to the bulb which has essentially zero resistance after being fired up and would end up oversupplying power to the bulb. Which could damage the bulb and/or ballast. (I’m picturing flames).

    I can provide a link to the thread I’m reading if you’d like. Just because someone wrote it on a forum doesn’t make it right, but personally I wouldn’t try this.

    It’s not as easy as putting a 20w incandescent bulb in a table lamp rated for 40w max.

    FOURSTARS Copepod M.A.S.C Club Member

    Thanks, that’s what I was afraid of, the ballast limits voltage through this tube. I have some HO t5 fixtures I was hoping to use on a Shorter tank. Glad I asked, that would of been a mess!
  4. TheRealChrisBrown

    TheRealChrisBrown Tuna Staff Member M.A.S.C Club Member M.A.S.C. B.O.D. B.O.D. Member-at-Large

    BRS sells replacement ballasts here. Maybe you can just swap out the ballast you need? I just bought one of the t5 retro fit kits which have some assembly required, and it was pretty easy to do. Wasn't too expensive.

    FOURSTARS Copepod M.A.S.C Club Member

    Thanks for the link, Those are pretty cheap.

Share This Page