My 90 Gallon Reef Tank!!!!

I always thought the same regarding airflow. The whole "hot air rises" notion. Then I saw how the Coralife fixture fan was blowing. One fan--situated top dead center blowing into the fixture. Two vents, one on either side, where warm air is forced out. When you put your hand on the sides of your Coralife fixture, Patrick, don't you feel warm air coming out? I do.

I'm no engineer, and I realize that Coralife is not Boeing or Lockheed Martin; but I imagine that Coralife had at least one engineer in on the design of that fixture. If blowing into the fixture is what they did, that's good enough for me. You also have a fan that's almost twice what mine is, as far as RPMs go. (You upgraded to an Icecap, if I recall). Anyway, if I were you, I'd have an open back canopy, and all 3 fans blowing air into the canopy. Sucking air out is passive. Blowing air in is active. If I were a hot bulb, I'd rather have a fan blowing on me, than a fan above me sucking. (Sounds rather perverse, I know. . .. )

As far as the fans go, give me a call when you're ready. It's easy enough. Get yourself 3 fans (or two, and hold on to that IceCap fan). I'd get 120V fans if I were you. That way you don't have to transform them down to 12V like computer fans require. It's just a matter of a hot and a neutral, and you can parallel all 3 off one "cord." I'll help you with that.

Another thing to consider, if you're going to cannibalize that Coralife fixture and rip out the reflectors, socket ends and bulbs for the halides, you might consider ditching the PC actinics, and using 4 or 6 54W T5's instead of the 2 96W PCs. They burn cooler, give higher quality light, and use less electricity. You'd need a ballast (one for 4, 48" T5 bulbs) 4 bulbs, and 4 good quality reflectors. I think the ballast is about $150, and the good reflectors are about $20 each. The bulbs are about $20 each too.

Something to consider. Or as you say, "food for thought."

 

this is true reefsparky.... When I upgraded my fixture I reversed the airflow inside that unit. They placed a fan at dead center of the main heat source in that fixture. I didnt want to puch all that heat through the fixture and out the sides. I wanted it to escape immediately. So I have air coming in through side vents and sucked out by the icecap fan. IMO it works well.

Thanks man... I knew this was right up your alley and I was hoping you would post on this. Thanks Im gonna take you up on this.

My initial cost with my new stand, canopy, fans, and my aquacontroller doesnt permit to do this beautiful upgrade. But now I know I have something to look forwad to in the future. I may do it when its time to replace my PC bulbs in about 5 months.

But i truly wanna do this. I do have to get retrofit reflectores for my bulbs. The aqualight reflectors glass shield doesnt stay on when out of the fixture. The fixture base itself holds it in. So I have to buy ones made for retrofitting which is only bout $40 a piece at aquacave. Heres a link look at how the glass shied is held in place. Remeber how your glass goes into place on your fixture. Theres a difference

250W Metal Halide HQI Parabolic Reflector with Lens - AquaCave

But yes that is truly food for thought. Thanks reefsparky

 

Thanks to reefsparky and powerman I have a revised rendering of my stand. No center support!!!! ;D

 

If you build it, we will come.

 

LMAO..................thats funny and clever. Luna

 

ok heres the canopy.....

my only ? is would you have a closed back on the canopy or open????

im gonna have an icecap fan on each side... one blowing in and one exhausting.

 

I'd go open back, and both fans blowing inwards. IMO the pros far outweigh the cons in the argument whether to have your top open or closed. Did you choose a canopy to prevent jumpers?

 

Reason I went with canopy is because I like the look. other reason also like... no more holes in ceiling frrom hanging lights. only reason I am having both canopy and stand built is because I am actually moving the tank to my new home at the end of this month.

But I am not sure on my airflow quite yet. So hopefully I get some good feedback on this.

reef sparky what you think about closed back... 2 fans blowing in with an exhaust on top directly between the halides???

 

It's a judgement call. Personally I don't care for a canopy, if I was forced to use one, I'd employ one that would have the least effect on gasseous exchange, and not contribute to containing heat.

I'm probably the wrong person to ask, since I'm biased against canopies because it's tough to have one that doesn't influence both. :-/