29 BC Temp problem

[hunkafish]

Ok guy's before i get to the problem, here are the guts of what I have running. 29 gal biocube, 2-nano korla's for flow, 2-36 watt power compact's one actinic,1- 10,000K, 11/2" Live sand and roughly 40 lbs Live rock Fiji cultured. Corals are 1 large rock with Zoo's all over 1 galaxia and a couple of green mushrooms. Fish One Coral beauty and one pigmy angel ( they get along great). I turn on the Actinic first for about an hour then turn on 10K 8-9 hours then Actinic for another hour alone then off. while lights are on I leave both lids open for circulation temp gets about 79. when i go to bed and lights are out with lid's shut the temp climbs to 80-81 in the morning. If I leave the lid up temp gets down to 76. I keep my A/c on all the time and keep it cold 70 night-75 day. My theory is the Live rock is acting as a heat sink absorbing the heat from the lights and then with the lids closed temp rises. Options are figure out away to stabalize temp, Ive been told to big a swing in temp is bad for the fish, so i nneed to address this asap, do i ad a chiller? do i get up at three am and close the lids after the LR has disapated its heat? I have ordered the Nano Tuner light upgrade kit with 2 more 36 watt lamps which will double the lighting also upgrading fans. There a couple of pic's in my gallery of the tank, any sugestions would greatly be appretiated

[dileggi]

I have the BC 29 as well. My lights are listed below in the current tank section. I run my white lights for 12 hours a day and the blues for 14...one extra hour in the am and one in the pm. I placed a small heater in the tank...I believe a 50w. I set that to 78 or 79 degrees. My temp hits 79.7 to 80.1 when my lights are running. They run with all lids closed. When my lights go off at night, my temp goes down to 78.1 to 78.7.

I don't know if you have a small heater in there, but I'm thinking if you close the lid while you're lights are on, your tank will hold more heat during the off hours.

If you're worried about the gas exchance, maybe point a power head upwards to break the water surface a bit?

I hope this helps and good luck.

[hunkafish]

Thanks Eric, What is your room Temp kept at?

[dileggi]

No problem hunkafish. Room temp is a little dicey at best. I live on the east coast and the tank is in my basement. While I do have AC there for the summer, I don't have any heat in that room where the tank is at. If I had to guess, I would say the room stays between 68-70 during the winter. In the summer it's at 70 with the central air going.

[hunkafish]

Ok last night I truned off lights except the 3 moon lights they stay on 24/7 left the back lid up above the sump area. this morning temp was 81 When I went to bed it was 78 the temp in my condo 72. where is this heat coming from? Tonight I will close back lid and leave the front one open. im looking at adding two fans in the back lid above the sump, one in /one out, that can run idependent of the lighting fans, that only run while the 10,000k bulb is on. I guess my question is are other people with Bio cube 29's having this issue? and what temp change is acceptable in a Mini reef with fish set up?

[hunkafish]

Three things contributed to the heat build up, after turning off the Hydor Nano pump's the temp dropped almost two degrees over 5 hours to 78.7 degrees corals look happier but Coral beauty is in a cave just hovering, I hope he/she is ok. I turned on the pumps again and temp started to rise, so the culprit has been identified. Tomorrow I'll clean them and run them in a bucket of water with temp probe and see if its one or both pumps. In addition I p/u a new sump pump Maxi-Jet 1200, a couple of people have told me it runs cooler than the stock Bio-cube pump. Now I will feel better ordering the light upgrade with higher capacity fans. The positive thing I learned from this is that with the lights on and the hood fans running the tank is cooler than with them off. Just goes to show how important air flow across the water surface dissipates the heat not just from the lights but also the tank itself. Bio Cube (oceanic ) should wire the fans on a temp sensor and or separate switch so you can run them all the time instead of only when both bulbs are on.

[nanotrigger]

you can get a chiller... after i got a chiller my temp stays at 78.