Coralife 10K T12 light???

[Boxster]

My 46 FOWLR Oceanic tank comes with a T8 flourescent light. I guess it is just the normal kind. So, I purchased a Coralife 10K flourescent T12. I don't know the 2 bulb is of different diameter but fortunately, it fits into my hood ( comes with the tank). The distance between the 10K light bulb and the reflector is much closer now compare the original T8.

I just change it yesterday and immediately I found that it is not as bright as my original T8? It is defintely more blueish in color but less bright. Anyone know why this is the case? I thought it should be brighter. Should I change back to the original T8?

One reason I change the light is because I have a diatoms problem so I thought it might be my light.

 

[MT79]

FWIW, I have heard nothing but bad about Coralife bulbs.

 

[Biggen]

As you increase color temperature value (e.g. K number) brightness decreases. Your old bulb may have been a 6400K bulb, hence it's yellow coloring. When you went up to 10K, it now gives a nice white/blue hue and it a little less bright.

BTW, brightness may be the wrong term to use here. Someone who knows a little more about lighting may be able to help me out.

 

[Guest]

The difference between the 10k and 6500k or original lamp that came with the fixture is only going to be the color..whiter/bluer depending on the manufacturer.. Now, I see you got a Coralife bulb... for NO Flourescent, they are quite good IMO...

What you may be noticing is the color change as opposed to brightness.. The 10K NO flourescents do not look real bright, yet they give off good intensity for a 40 watt bulb... It is more like the depth in which the fish and corals come from ..

I guess the best way of thinking about it is,, yu are now viewing what it would look like if you dove down 20 ft into the Ocean as oppsed to 5 ft down..The intensity is there when the brigthness isn't...

 

[Biggen]

What you may be noticing is the color change as opposed to brightness..

I knew brightness was the wrong term..

 

[Boxster]

Thank you. I am more at ease now. I am assuming that it is ok to use a T12 instead of the T8 that is on the original hood. The ballast is rated 30W and my 10K is also rated 30W also.

 

[Biggen]

am assuming that it is ok to use a T12 instead of the T8 that is on the original hood.

It really depends on the ballast. If the T12 fired up and is still burning, than the ballast seems to be able to handle it, so I would say, "Yeah". Although this isn't always the case. The top of the ballast should tell you what it can run.

Some ballasts are bulb specific (i.e. can only run one type of bulb at a certain wattage) while others can run different bulbs and even accept different input voltages. For example, my multi tap metal halide ballast (M58) I is able to run both 250w metal halide and 250w mercury vapor bulbs. However, this is mainly because MH and MV are nearly identical except for the gas that is inside their quartz sleeve.

 

[Guest]

Nope,,,,

T-12's at 48" are almost always 40 watt bulbs and I know Coralife are....

If the ballast is rated for 30 watts, it is a T-8 ballast and therfore is for 32 watt bulbs.. T-8....

Some ballasts are rated for either, but if you are sure it says 30 watt, this is the reason for the change in brightness you are experiancing, because the lamp is being under powered...

 

[Guest]

The 36" bulbs are 30 watt. My bad

 

[wseaton]

I doubt if it's a ballast problem with such a straight forward bulb. If we were trying to drive a T5 with a 24" PennPlax hood I'd say otherwise. A 10K T12 is not going to be a very bright bulb in the first place.

I'm also not sure why Coral-Life gets all the bad press either. The major bulb manufacturers all have access to the same phosphors and other industrial supplies required to make their bulbs, and there are hardly trade secrets left anymore with florescent technology. Coral-Life's actinics are superb in my experience.

What we need is a bulb that has no middle of the visible spectrum vs that full spectrum garbage that has no purpose on a marine tank other than for growing hair algae.

 

[MT79]

URI....why pay more for less? (a name)

 

[wseaton]

I primarily use Coralife PCs and have never seen any documentation that shows any particular advantages/disadvantages over any mainstream high output florescent tubes vs the other.