Actinic Bulbs

[whip]

I purchased a used 55 gal aquariium. The previous owner used it for saltwater, but I have it set up for fresh. I received a bunch of other things with the tank, including a few extra flouresent bulbs. The light strip is a two bulb setup, and i'm using a standard aquarium bulb. Two of the tubes he gave are "super actinic R". Can these be used with freshwater? Will they cause problems? I'd hate to have to throw away a good bulb.

 

[SkiFletch]

They can be used for freshwater no problem. They make things look a lot "blue-er" and sometimes will bring out phosphorescent colors better than standard bulbs. So long as you're not trying to grow freshwater plants, they should be just fine

 

[whip]

I'm not growing any plants. How would it hurt plants?

 

[SkiFletch]

I'm not growing any plants. How would it hurt plants?

Wouldn't hurt them, but actinic light isn't the best choice for growing most freshwater plants. Freshwater species tend to prefer bulbs with a color temp around 6700K while actinics usually have a 20000K rating. You get a better mix of blue and red wavelengths on a plant grow bulb (blue and red are used by clorophyll ). Having only blue is not as good as having blue and red

 

[Lateral Line]

There are, however, certain algae species which seem to flourish under Actinics. Keep an eye out for that.

 

[whip]

That makes sense, and leads me to my next question. Is it possible to have too much light? The tank almost glows, and the fish seem very spooked. Should I ditch the actinic?

 

[SkiFletch]

That makes sense, and leads me to my next question. Is it possible to have too much light? The tank almost glows, and the fish seem very spooked. Should I ditch the actinic?

No such thing in the marine world IMO. Dunno about your fish though, what are you keeping?

 

[Lateral Line]

It does depend a lot on what you are keeping. Tropical open water fish get the full glare of the tropical sun, which is pretty intense. Actinic lamps are designed to replicate the open water conditions over coral reefs where the water is a little deeper and has absorbed much of the red end of the spectrum, thus you can have full sun, deep water conditions indoors and in a shallow tank.

Most of the common smaller fish are not open water though, they frequent undergrowth and plants where the light is lower and they have a lot of escape options. Others are rainforrest stream species, and from experience, I know it can be pretty dark on the rainforrest floor at any time of day. If it is these we are talking about then yes, in very bright light in relatively bare tanks, they will be stressed.

I would get rid of the Actinic lamp(s) simply because they create such an un-natural picture when looking at the tank, but that is a matter for personal æsthetics.

 

[whip]

I have some silver dollars and clown loachs in the tank. I'll give it a day or two, and remove it if they still look stressed.

Thanks for all of the help.