T5HO Bulbs in a T5(no) Fixture?

eeyipes

AC Members
Jun 11, 2008
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Washington IA
I currently have 2 - 18w 6700k T5(no) bulbs in a 30" NO strip light for my 36g low light tank. The plants are doing well, but I'm not really enjoying the yellowish cast they put on everything ... my dwarf blue gourami looks almost green sometimes. I'd like to switch one or both of the bulbs over to 10k in hopes of getting a better look, but for some reason I'm having a heck of a time finding normal output, T5 30" bulbs in a 10k, for a decent price or with reasonable shipping costs. I am finding plenty of T5HO bulbs tho. I should probably just upgrade my light strip but I really don't want to right now.

Can the T5HO bulbs be used in a T5NO fixture? Will they pop, or just not shine as bright as they would in an HO fixture?
 
I've been told it does not work to mix HO bulbs in NO fixtures (or vice versa) because they use different ballasts and those and the bulbs must match. If I understood the explanation correctly. But at any rate the answer was a negative.

alas. and my Coralife T5 30" is officially ruled a piece of junk: the 10K white bulb burned out within a month of purchase, so I was running the actinic over my 1og salt tank (with the t12 1 bulb strip that came with the tank. Yeah it looked goofy but it worked.) Now the actinic has burned out AND managed to melt a piece of the plastic protective strip. bah. and also, humbug.
 
Bah humbug is right. I like my skinny little cheapo low tech striplight. Maybe I can get the LFS to order me some cheap. o well
 
30" bulbs seem to be hard to find despite 20 longs being so popular...add to the fact that NO is much less common than HO...there isn't much variety. I ended up going with the Coralife bulbs on Amazon when I had to replace mine.
 
thanks jpappy, I am just going to get a new fixture for the 29g. The one that's on it is 30 in fixture but uses 24 in. bulbs which are common as dirt, and it actually does a pretty decent job of lighting up the tank even at 12T and not excessive wattage. But not a coralife. /ack spit ptooey.

But back to OP's q uestion, it is correct that NO and HO cannot be mixed betwen fixture and lighting ? I am some distance from an expert on matters electrical so confirmation would be nice. :)
 
Haha, my Coralife fixture seems to be doing alright. Bulbs didn't burn out until about a year into use which seems typical for T5s.

But I'm no electrician either...I figure that you should stick to what things are intended to be used for when it comes to something so potentially dangerous. Hopefully someone else has something more concrete than that...
 
Can the T5HO bulbs be used in a T5NO fixture? Will they pop, or just not shine as bright as they would in an HO fixture?

In general, but not always, T5 lamps can work in either a T5HO or a T5NO fixture.
In general, current fixtures use electronic ballasts that essentially read the lamp and adjust for its electrical characteristics.
That means a T5HO lamp in a T5NO fixture lights at T5NO output.
................a T5NO lamp in a T5HO fixture will be brighter than it would be in a T5NO fixture, but not by much.

And, yes, I've been there and done that. I keep only T5HO lamps on hand, for a mix of fixtures. It's simpler and cheaper. Lamps, by the way, are cheapest at hydroponics stores.
 
Coralife is the only manufacturer of 30" HO T5 or NO T5 lamps. All other brands use 24" lamps. Dbosman is correct that a NO T5 fixture will light either HO T5 or NO T5 lamps. The HO T5 lamps will not be driven as hard and will only be moderately brighter (if at all) than the NO T5 lamps. However the filaments will not degrade as quickly (HO T5 lamps have thicker filaments) and the lamps will last longer.

NO T5 lamps driven on HO T5 ballasts will burn out more quickly but will be just as bright as HO T5 lamps.

The lens melting issue on Coralife NO T5 fixtures is something we are aware of and is due to defective or old bulbs. As the lamps age the filaments run hotter in order to remain lit. If the filament gets really hot it will create a localized hot spot and get hot enough to soften and melt the acrylic lens cover. Running a two lamp fixture with just one lamp will do this as the current through the remaining lamp will be higher than when two lamps are being lit.

Newer Coralife NO T5 fixtures are using a higher temperature resistant lens and the endcaps have been redesigned to double the distance between the lamp and the lens. We have not been able to duplicate the lens melting issue with the new fixtures (Even when running in a 100+ degree temperature controlled room). These fixtures have been shipping for about 5-6 months now.

If you are looking for a whiter look to the tank I would consider replacing one or both of the 6700K lamps with 10K lamps. Both lamps have a similar spectrum but the red and green light is slightly reduced in a 10K in favor of blue compared to the 6700K which gives it a cooler (whiter) look.

Andy
Central Aquatics R&D
 
From what I've experienced playing with HO & NO, HO bulbs will work in NO fixtures, at a greatly reduced amount of light, and greatly reducing the life span of the HO bulb. I also noticed that an HO in an NO fixture produced less light than a properly matched NO bulb would have.

As for doing the reverse, using an NO bulb in a HO fixture, I've never gotten one to so much as light up.
 
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