refugium light?

[bb72]

My LFS is telling me that if I want to keep corals I need to change my refugium light. I have never figured the gallons for the refugium but it is 13 x 12 x 19 in a 29 gallon tank. Personally I think he is just trying to make a buck. Right now I have a hood from a perfecto twenty gallon tank with a coralife 6500 bulb. He is telling me I need to switch to the coralife 65watt with a 50/50 actinic bulb. Also I would like to know what the formula for figuring out volume in gallons, if anyone knows, so I can know how much water is in my refugium. My refugium is growing just fine am I wrong or is he trying to make some money.

[Sueet]

My LFS is telling me that if I want to keep corals I need to change my refugium light. I have never figured the gallons for the refugium but it is 13 x 12 x 19 in a 29 gallon tank. Personally I think he is just trying to make a buck. Right now I have a hood from a perfecto twenty gallon tank with a coralife 6500 bulb. He is telling me I need to switch to the coralife 65watt with a 50/50 actinic bulb. Also I would like to know what the formula for figuring out volume in gallons, if anyone knows, so I can know how much water is in my refugium. My refugium is growing just fine am I wrong or is he trying to make some money.

You're not wrong, he's trying to make money. If it aint broke, don't fix it!

[Ninong]

To calculate the volume, multiply the length times the width times the height in inches and divide by 231. That will give you gallons. (There are 231 cubic inches in a gallon.)

If you have macroalgae in your refugium, almost any kind of daylight light will suffice. You really don't need actinic light for macroalgae. I have no idea what the LFS dude is thinking unless he thinks you are keeping corals in your refugium???

[bb72]

No, there are no corals in the refugium. None in the tank yet either, but soon I hope! I just want to make sure things are right before I add any, dont see the point in buying something to watch it die. I have one more question. Do Amphipods, or copepods molt? There are always two or three of them floating around the tank. The fish I have will take a bite and just spit it out, and not eat it. Is this just a shell floating around? There is no color to it, it just looks like a clear shell.

[Ninong]

All crustaceans, regardless of size, molt. So yes, amphipods and copepods do molt. You might be seeing an amphipod exoskeleton if you have good eyesight. I doubt that anyone could spot a copepod exoskeleton without a magnifying glass or a microscope.

[bb72]

Thank you Ninong, I was just curious about that.
You said if I have good eyesight I might see one? How big do they get? I pulled one out the tank the other day to look at it and it was about a quarter of an inch long. Am I refering to something else that may not be an Amphipod? Like I said there are always at least two or three floating around the tank, might it be somthing that I dont want in the tank? What I am looking at has a large abdomen(?) about six legs and a smallish head.

[Ninong]

Thank you Ninong, I was just curious about that.
You said if I have good eyesight I might see one? How big do they get? I pulled one out the tank the other day to look at it and it was about a quarter of an inch long. Am I refering to something else that may not be an Amphipod?

That sounds like an amphipod. They look like tiny shrimp that are laterally compressed. They range in size from about 1/8" to 3/8". Copepods are much, much smaller and have five legs sticking out from each side of the body. You would only know this if one of them was on the glass and you looked at it with a magnifying glass or you were able to put one under a microscope. My eyesight is not good enough to make out a copepod's features in my tank. I can tell which ones are amphipods and the really tiny ones scurrying around the rock and the sandbed at night would be copepods. To me they are just moving dots.



P.S. -- The comment about "good eyesight" is more a comment about the fact that I do not have good eyesight.

[bb72]

Oh, ok. Thank you for the response, Ninong. That is what I am seeing in the tank. I have seen copepods in the tank at night with a red flashlight. I was actually kind of amazed at how much tiny life coms out after the lights go out.