Fan layout on a canopy

[reefinatl]

So I decided to do a canopy so my whole room isn't blue and you aren't blinded seated and looking up at the tank. Worked great, except now I'm learning all about heat from halides. Never had a heat problem back in the day but then I ran pendants with no canopy.

So as it is I run two of these, one in each top back corner.

https://www.amazon.com/gp/aw/d/B07CG2PGY6?psc=1&ref=ppx_pop_mob_b_asin_title

I just bought two more fans, but not sure where I want them. The two currently in there suck air out of the canopy. I'm thinking I'll mount these other two in the back along the bottom to blow air into the canopy right under each pendant.

Temp swings are about 10*, trying to stay in the 5* swing range.

 

[redfishbluefish]

Best if fans are always blowing in. The reason is fans blowing out is with salt laden air which will cause premature failure of the fan.

Now, as far as some blowing in while others blow out....is a waste of fans. You just want a passive means to rid the canopy of air.....that is, some hole or opening is all you need. Let me see if I can explain air in/air out waste. Let's say, and just to pick numbers, the fans blow 50 gazintas (made up name) of air. So if I have two fans blowing in at 100 gazintas, and two fans blowing out at 100 gazintas, the turnover is 100 gazintas.....100 IN, 100 OUT. Now if I take these four fans and have all blowing in, that's now 200 gazintas of turnover.....200 IN with fans, 200 OUT passively. See how some in, some out, do nothing? Hope this helps.

 

[reefinatl]

Gotcha, I guess I was looking to get pull hot air out while drawing cool air in from the bottom with the initial setup.

My thoughts with adding fans blowing in and keeping the first two as exhausting was speeding up that process.

Maybe I was wrong in that approach.