T8 Florescent bulb in a T10 Light

[cutlassvillager]

We have a 55 gallon fish tank that has a florescent light on the top that originally had a T10 40w bulb in it. The light stopped working so I went to get a replacement bulb locally. Checking all around there were no T10 bulbs to be found. After checking Lowe's, Home Depot, ACE and even a local lighting supply company I went to our local pet shop who said that as long as the wattage is the same a T8 bulb will work in a T10 light.

I put the 40w T8 bulb in the light and when I turn it on just the edges glow a very dim light and occasionally flashes. I don't have any other lights to test the bulb in. Should I order a T10 bulb online, or does it sounds like it is a problem with the ballast in the light and I should just get a replacement light/bulb?

 

[eljefino]

T10 is a real wierd size. I'd get a "universal" ballast that says it'll run a T8 or T12.

You probably have a magnetic ballast in there which can't cope with the modern T8.

As long as you're at it though, flick the switch a couple times real quick, maybe it'll catch.

 

[440Magnum]

T10's are oddball, fairly common with aquarium lights there but only for a few years. T5 fixtures are the hot thing now.

But to the point, a T8 should probably be fine if its an electronic ballast. The fixture itself may have in fact been built for either t8 or T12, or with a unviersal electronic ballast.

As eljefino said, magnetic ballasts are part of a tuned circuit and can't adapt to different bulb sizes. If the lamp is too low impedance (bigger diameter) then the ballast will overheat, if the lamp is too high impedance (smaller) then the lamp life will be short. Does the lamp snap on instantly, or is there a flicker at startup? Flicker = magnetic ballast.

 

[JTK]

Cutlass, that must be a real old fixture. Dunno that I've ever heard of a 48" T10 fluorescent tube.

Google "Odyssea 48" T5HO". I've got one on my 55gal tank. ~$57 shipped to your door with twin 6500K T5HO lamps included. Real nice fixture for aquatic plants. Awesome for the price.

 

[cutlassvillager]

Thanks for the quick replies everyone! The build date on the fixture is Oct of 2007. I found some information on the fixture. All it says is: Aquarium Equipment Model: 48psdx. I did a quick Google search and didn't find anything of substance.

I tried flipping the switch a few times quickly and I can get it to flicker for a second (just on the ends) but that's it. After the flicker the ends just glow very dim, similar to a incandescent bulb. Should I maybe just take the fixture apart to figure out what kind of ballast is really in there?

 

[JTK]

You could try to re-ballast the fixture, but it's not worth the effort IMO. Today's electronic ballasts are genuine JUNK. Keep in mind you can easily just use a 48" shoplight fixture for a 55g tank. It will rest edge to edge. Best to throw a section of plexi or glass between it and the water though.

If your tank is planted, T5HO is the way to go. Here's mine with my ~$57 Odyssea fixture:

 

[cutlassvillager]

Thanks for the suggestion JTK. I will check out the Odyssea fixture. Your tank looks great! My tank is planted, however the plants are fake so I don't think they'll care too much what kind of light is shining on them.

 

[JTK]

Originally Posted By: cutlassvillager
My tank is planted, however the plants are fake so I don't think they'll care too much what kind of light is shining on them.


LOL! No they sure wont. Go with a pair of Marineland LED hoods for your 55g if you don't plan on live plants. They use basically no electricity, don't heat the tank like a T5HO does and they look great. You can get LED fixtures that support plants but they're very expensive. Typical pet store LED tank lights will not support plants. They don't kick out enough PAR.