HQI Help

[pikachusalad]

I've had very bad experiences buying used equipment...so I need to ask you guys first.

I'm (eventually) getting a 75 gal tank. Someone locally is selling 2 150W Aquamedic HQI pendants, 8 months old, 20K bulbs, for $100 each. This sounds like a great deal, since they're like $250 new.

What do I need to know about these lights? What do I need to know about 150W, vs. 175W or higher? What do I need to watch out for? Will these be good lights for a 75 gal tank?

 

[Randall_James]

150W should be just fine, what to watch out for:

Age of bulbs: 1 year max, then they go in the trash or on the shelf as emergency backups

Glass covers: Never run these lights without the glass (HQI DE) cover due to UV radiation, it will in fact kill off your tank if allowed to operate without the covers.
Depending on the age of the bulbs, it could be a great deal or just a fair deal.
At 8 months old, the bulbs are 3/4 used up so you can count on replacing them pretty soon.

Price new stuff and then compare. I know you can buy bare pendants for around $100-115 each. (I just bought 2 new Lumenarcs from saltycritter.com for 300) Used lights can be sort of tricky so just keep your eyes open and shop hard

 

[NDreefer1]

Those are definately good lights. Whether they are good for you depends on the type of corals you want to keep.

If you want to go SPS dominant you MIGHT get away with eventually switching to 10K and using some supplemential actinics. Otherwise you would likely be restricted to keeping SPS in the top 6" of the tank.

If you want more softies/zoa/LPS, the 20Ks will be decent, and I'd say one of the 14k bulbs would eventually be perfect replacements for a mixed reef. FWIW I have 250W DE 14ks and almost killed a brain on the sand (30" from the light), and in retrospect I might have gone with the 150Ws since I ended up prefering LPS over SPS.

Heat becomes a concern at things larger then the 150/175W too, so that might be a factor. Keep in mind as well a 150W DE is approaching a 250W SE due to better reflector design, so It might not be as weak as you imagine...

- Bob

 

[pikachusalad]

Is there a way to tell when they need to be trashed (or shelved) or is it just based on time...?

 

[NDreefer1]

Different bulbs have different recommended lifetimes. Generally halides last about a year. Obviously if you have a 6hr or a 12hr photoperiod that will affect things, though halides also are impacted by each on/off cycle. Generally the lower K bulbs last longer, something with the phosphors used...

Its a subtle shift. Generally things start looking less blue,more ugly yellow. Alage tends to do better with older bulbs. so you might notice increased growth. Evenually corals will start to suffer....

8 month old bulbs should be good for another 4-6 months, at which point you can decide to keep that same color temp or go with something else.

The fixture itself will last years...