Well I see what your saying but why would anyone buy anything that gets too hot to keep anything in. That just doesnt make sense. Im wondering if Matt is on to something with the pumps being old and heating up too much. The biocube doesnt have MH and its heating up too much as well.

Don't forget to plug your heater back for the night.

1. Metal halide
2. Pumps heating up
3. Closed canopy
4. Fans not doing its job
5. Less than adequate evaporation
6. Less surface aeration

Theres nothing in it yet so heat doesnt matter. Has anyone bought either of these brand new? Do they over heat right out of the box?

All of the biocubes that I had were just fine out of the box. I even did a MH retro into a BC29, and it was totally fine on its own.

Whats your house thermostat set at?

Two things I would do:

1. Make a small gap inbetween your canopy and tank. This allows airflow onto the surface of the water

2. Upgrade your fans

To tell you the truth, I instantly upgraded the fans when I bought my biocubes. I found them noisey anyways. Theres lots of threads on fan upgrades out there. www.nano-reef.com has an excellent biocube resource section that you could look at as well.

Also check the direction of the fans. I believe 1 should be blowing into the tank and the other bowing out. You might want to flip them around in difference combos to see if that helps

As far as I know the nano cube hqis were designed from the factory to use a chiller. As far as the bc8 goes, I'm guessing its running pc bulbs.... They get pretty hot, running them in my bc14 I didn't need to use a heater

Don't know much about the NC28 but for the BC8, try popping the back part open and leave it open. You could even add a fan there to blow extra air over water but it will increase your evap so ATO necessary.

The fans in the hood are too cool the PC bulbs, not the tank. They are noisy and if you are going to replace them, just buy the same size ones from a local computer store. Spend a buck more and get a controllable fan with actual bearings.

I would check the pumps, might just be worth swapping it out. MJ400 or 600 should probably be enough flow (I'm only running a MJ900 on my BC29) and they are relatively inexpensive.

Just my 0 cents (2 cents round down now that we don't have pennies... lol)

Thanks everyone. Today I got home and it was 80 in the bc8. Yesterday I swapped the stock pump out for a mj900. Seemed to do the trick.(thanks Matt) Yesterday I cleaned the fans on the nc28, but the lights werent turned on today until I got home from work. So I will be monitoring these tanks closely. If all else fails I will either find an led kit for the hoods or just take the hoods off and get aftermarket lights for them.

Had the same problem with my bc14. after a year I gave up even after switching over to LED's. couldn't get the temp under 82. switched to an innovative 16 and I had to add a heater because it wouldn't go past 71.

The closed canopy is a huge issue, really creates a little oven. Unless your willing to add a chiller, I would look into something like a AI nano or something on those lines to get rid of the canopy.