bulbs for Coralife Aqualight for freshwater tank

[Jennewt]

I volunteer for a nature center, and we got a free 180-gallon tank that came with a 6' Coralife Aqualight fixture. It was previously a saltwater setup, but I'm converting it to freshwater. The fixture came with actinic bulbs, but these are obviously not what I want. I'm lost with the array of bulbs, and I need to purchase carefully as my budget is very limited.

The main consideration will be appearance - illuminating the fish. Secondarily it would be nice if we could keep some hardy plants alive. To keep costs down, I would like to install only 2 bulbs, rather than the 4 that the fixture can hold.

Here are some of the choices available. What should I buy?
10000K
6700K
Colormax/6700K (a 50/50 bulb)
6700K/10000K
... and maybe there are other options out there I should look for??

Other questions: if I use a 6700K bulb, can I plug it into the half of the fixture that does NOT run the fan? I think the fan is intended for running 10000K bulbs and the non-fan plugs for running actinic. But the manual doesn't tell me whether the fans should run for 6700K bulbs.

Would I save money in the long run by getting a different fixture that takes cheaper bulbs?

 

[dudley]

I have the same fixture and replaced the Actinic bulbs with the 6700K bulbs and I'm pleased with how it looks, though I did install the 6700K in the front & the 10000K in the rear.

Regarding the fans, while it is not mentioned in my operating instructions, I contacted ESU (mfg./distr.) about HOW to run the fans. The email I received from them stated the fans are only on when the front lights are on and they highly recommend always running the fans. This is to dissipate any heat in the fixture and failure to do so will shorten the life of the unit and void the warranty.

My fixture is on a 220G tank, 30" high, and I did not have good results growing plants. I tried Java Fern and Anubias and could barely keep them alive in the tall tank using all 4 lights. Other people may have better success though.

 

[Jennewt]

Thank you Dee, that's very helpful. How often do you need to replace the bulbs?

 

[bradlgt21]

Bulbs typically should be replaced about once a year. If you don't have plants you can stretch it but old bulbs tend to lead to algae. I would suggest running a 6700k and a Colormax bulb. This is what the freshwater setups from aqualife come with. The colormax is a great bulb. It has a better overall light spectrum and more peaks in the reds and a higher peak in the blue then the 10,000k. It is a good combo with the 6700.

 

[Crispino Ramos]

Plants will utilize any kind of light. IME, the 6700K bulb is the most pleasant for viewing. I remove the splash guard and it helps cool the ballast without the fans.

 

[dudley]

Thank you Dee, that's very helpful. How often do you need to replace the bulbs?

Since I do NOT have live plants in this tank, I only replace the bulbs when they burn out.

 

[Jennewt]

Thanks all!