Lighting clarification needed

[lmetcalf]

Hey all,
I Need help figuring out some new lighting for my 30 gal (30 inches long, i think it's 18inches deep) tank. All the acronyms confuse me and the wattages and whatnot.

Right now i have T5's (i think. the bulbs are two long skinny tubes that are attached at one end). There's two bulbs, they overlap a little in the middle. I didn't buy this fixture so i don't know what the wattage is or anything.

I would like to have clams, but I'm prepared to keep them high up in the tank. What kind of lighting do i need? What is my cheapest option?

 

[lmetcalf]

Someone said i should have 4 watts per gallon. Is this reasonable? Anyone know what i currently have?

 

[ccCapt]

If they only plug in at 1 end, they are PC (power compact) bulbs. They are OK if you only want to keep some soft coral polyps and mushroom type corals. If you want to move up to hard corals, you need T5HO. The watts/gal thing is old and outdated and is really only a good estimate if you are using normal output fluorescent or power compact bulbs. Once you move into T5HO or metal halide or even LED's, you are more concerned with PAR, not wattage.

You probably have 2 x 65w power compact.

 

[Aquarium1]

Once you move into T5HO or metal halide or even LED's, you are more concerned with PAR, not wattage.

Just curious, how do you calculate PAR?

 

[cmor1701d]

You don't calculate it, you measure it. "PAR stands for photosynthetically active radiation. It is the amount of light in the 400 to 700 nanometer wavelength...
PAR values range from 0 to 3,000 millimoles per square meter. At night, PAR is zero. During mid-day in the summer, PAR often reaches 2,000 to 3,000 millimoles per square meter...
PAR is measured as millimoles of light energy per square meter. PAR is measured by a silicon photovoltaic detector. This detector measures light in the 400 nanometer to 700 nanometer range."

 

[Aquarium1]

Ok, thanks cmor .

 

[lmetcalf]

ok, soo.....after all that, what do i need on a tank that's 18inches deep, for a crocea clam placed at least half half way up? What about a durassa clam?(cheapest option)

 

[AMDPhenomX4]

A Crocea clam needs halides as its the most light demanding clam I know of. The power compacts you have now should be fine for some LPS corals. Frogspawn, Trachyphyllia, and Favias to name a few.

 

[ccCapt]

ok, soo.....after all that, what do i need on a tank that's 18inches deep, for a crocea clam placed at least half half way up? What about a durassa clam?(cheapest option)

For a crocea clam, you need T5HO at least. A derasa is a lower light clam and you "might" be OK with your current lighting, but that's taking a chance. Also, they get HUGE and your tank isn't really big enough to be able to keep it very long.

A Crocea clam needs halides as its the most light demanding clam I know of. The power compacts you have now should be fine for some LPS corals. Frogspawn, Trachyphyllia, and Favias to name a few.

I disagree. I don't think 2 PC bulbs is enough for LPS. It may keep them alive, but they won't thrive.

 

[lmetcalf]

in my tank now, the mushrooms seem to be moving away from the light, and my kenya tree is going nuts. I've had it for a few months and it's grown more than twice the height and made 4 babies. Given that, what other corals do you think would do okay in my light? I haven't had much luck with zoo's, they just seem to disapear in my tank. Any other ideas?

 

[tryin2make63]

okay i am sure i am not the only one wondering this...can someone explain the difference between

t5
t5ho
pc
metal halide

what one is better, do one cause more alage groth than the other.