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Mostro 11-28-2012 03:04 AM

Par30 and Par38 Users
For those hanging Par30 or Par38 bulbs (21-36w) over their tank, how much shimmer are you seeing? At what height does the shimmer diminish or disappear? I likes me some shimmer (MH lighting over a reef is one of the memories that brought me back to the hobby) and it's one of the reasons I've been planning to use these bulbs.

However if it can't be had (the shimmer, that is) at the height I'll need to hang my pendants for good coverage (roughly 32 inches over the substrate on an 18" tall tank) I might just as well plug in a Finnex Ray 2 and call it a day. Those seem like great units, but with such a diffuse coverage of 1w emitters, don't have the point source output that will satisfy a shimmer-head. Or so it seems.

DogFish 11-28-2012 03:28 AM

My lights are about 16" above my tank and I have some shimmer. I don't have the surface turbulence that most reef tanks do so the effect is less of course. I've never had a reason to have the lights higher so I can't tell you when you might lose the effect.

If you decide on the Finnex Ray 2 instead, I think you will be very happy.

Mostro 11-29-2012 10:40 PM

That's great to hear. I was hoping you would post as your lighting setup inspired my plan for a pair of hanging pendants. I'm planning to use two of these fixtures, but I'm thinking about drilling some ventilation as I'm concerned about heat build-up shortening the life of the emitters.

DogFish 11-30-2012 12:01 AM


Originally Posted by Mostro (Post 2093697)
....I'm thinking about drilling some ventilation as I'm concerned about heat build-up shortening the life of the emitters.

So are those going into ceiling boxes? If so really get a good feel for the light coverage. For a 36" tank and 30degree lens I would suggest 3 lamps. The reason I went with a track light is I get the ability to use lateral movement in placement since Im using two pendants. I agree with ventilating the fixtures.

At one point I thought about the classic 50's pool hall light fixture with 3 glass green shades. That just wouldn't look right in our living room, so I went with the IKEA shades.

Mostro 11-30-2012 02:31 AM

No fixed boxes here, these pendants will hang from ceiling track using 110v pendant converters to light a 24" long tank. The pendant height will remain adjustable, at least until I get it dialed in and cut cords to length. The bulbs I'm looking at feature 5300k 60 degree Cree emitters, in either a 21W PAR30 or 36W PAR38 configuration. An inline dimmer and wall switch timer will control intensity and duration.

Regarding the tank itself, I'm still vacillating between the 17g "60p knockoff" from Mr. Aqua, and their larger 33g tank which has the downside of being nearly 18" deep front to back. The larger tank is a better fit for the stand I'm modifying, and a better fit in many other ways as well. So I'll probably just deal with a slightly dimmer front and back than could be had with the 12" deep (f to b) 17 gallon version. In other words, the bulbs probably don't have enough spread to cover 18" front to back, but I hope I can work around that.

Frankly, I'm flying by the seat of my pants to set up a tank over a 3-4 period based on whatever I think I've read, so I expect to make some mistakes. I'm just trying to prevent really expensive mistakes...

DogFish 11-30-2012 03:42 AM

My apologies I confused you with another member that had 30degree PAR38s.
Your 60degrees may be closer. Maybe start @ 8". Of course before your start cutting the cord.

If you are able to get Dimmable Bulbs it's worth the extra $. HomeDepot has Dimmer switches for LEDs.

Sounds like you are good to go. Back when I did mine I could not find pendant converters for the Track I bought. I bought two pendants then swapped in the IKEA cords.

Mostro 11-30-2012 04:42 AM

No worries, thanks for the tips. At the moment, I am much more comfortable with the equipment side of the equation than I am with stewarding the amazing life forms all this stuff is designed to support. We'll see what happens next month. I can see from not only your tank but also your other projects that you're a true green (and maybe occasionally brown?) thumb. :wink:

DogFish 11-30-2012 02:06 PM

Thanks, if I have any success I credit doing my research and keeping it simple. It's not rocket science, we keep aquatic weeds and bait fish that come from 3rd world drainage ditches, fertilized with water buffalo dung. :smile:

Also, I've posted more than once, it's a system, don't fixate on 'parts',
look at how they interact.

Micro managing may be the worst roadblock on the path to Aqua-happiness.

Best of luck on your new tank, Pm me when you get a journal up.

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