Lux meter- am I doing it right?

[DracoKat]

I put the meter on top of the screen top for first reading.

then I moved the light fixture and held the meter down to where the bottom of the tank is to get the bottom reading. Considering I didn't have an extra hand to help me out, only partial of the light was exposed to the meter.

Did I do that right?

and.. to the readings, is it enough for clam or nem? What's the minimum reading should I aim for?
I have it set to 50000. Not sure what these settings are.

 

[saltyfilmfolks]

Yes. It looks like you have 49000 lux at the top. If it's a black box led that approx 800 par. (Devide by 60) if it's t5 devide by 50.

Plenty of light for anything.
Not sure how deep your tank is so can't tell you what to aim for at the bottom. 600 to 800 par at the top of a 24 in tank is plenty of light for anything.

As far as the bottom reading if it's next to the tank it's prob not too accurate.

 

[DracoKat]

thanks you!

Its 4 bulb HO T5's. which would be 980 par?

Tank is 21 inches deep. not sure if there's a math to figure out the par at the bottom?

 

[mcarroll]

That reads almost 50,000 lux.

Move the sensor around the top and map out the intensities of a few key zones...like the middle and the edges...angle the sensor as needed to get the highest reading you can in each spot.

I don't worry about measurements except for those at the water surface.

 

[saltyfilmfolks]

You would have to put the sensor on the bottom to gat a lux reading. Or point the whole fixture away from the tank and put the sensor the same distance away. (Testing dry).

Yea. That's a lot of light. Acclimate corals carefully feed well and dose!

 

[DracoKat]

thank you all!

I'll get a better reading at the bottom when I get some help to hold the light fixture for me (it's 48 inches long), I can't do it myself.

but I am happy to hear it's enough light to host anything. thank you!

 

[mcarroll]

T5 PAR will vary by bulb combo so an exact conversion might be different.

For simplicity I always use a conversion factor of 50....thats about the conversion factor for sunlight, so I figure that might make it a bit more universal (if not accurate). 50 makes for easier math too.

 

[DracoKat]

Thanks. I am going to figure out what combo T5's I should try out.

 

[mcarroll]

To answer the question about clams: I think 30,000 lx and up should make them happy but I'm going from memory on that.

You are definitely in the right neighborhood for them.

 

[mcarroll]

Thanks. I am going to figure out what combo T5's I should try out.

Do you know what your local reef store carries?

 

[DracoKat]

Do you know what your local reef store carries?

I'm not sure exactly, I glanced but didn't really look. one of them had a wall full of T5's. if I can find some combos, I can see what they have and finalize the lighting based on what they have in

I am sure they do not have ATI's, but they do have a lot of coralife bulbs and another brand I can't remember at the moment

 

[DracoKat]

Hey all,

I changed my lights. Can someone tell me if the lighting is now better for clams?

2 ATI blue+
1 ATI Purple +
1 ATI Coral +

Reading at the top: 878 x100 lux
Bottom is 35 x 100 lux

 

[saltyfilmfolks]

87800 lux? and 3500. sounds off. the last measure is outsde of the tank?

 

[DracoKat]

Yea outside the tank. It's hard for me to measure without someone helping me hold the light

 

[saltyfilmfolks]

Ill go back to this.

Yea. That's a lot of light. Acclimate corals carefully feed well and dose!

its a lot of light

 

[ksc]

Ill go back to this.


its a lot of light

It's another grossly inaccurate reading by a lux meter. An ATI t5 fixture puts out about 700 par max at the surface and maybe 250 on the sand (21" deep tank).

 

[DracoKat]

it's either inaccurate, or I am just not doing it right.

thank you @ksc !

 

[saltyfilmfolks]

It's another grossly inaccurate reading by a lux meter. An ATI t5 fixture puts out about 700 par max at the surface and maybe 250 on the sand (21" deep tank).

at what distance from the fixture to the top of the tank?
I did say it sounds off.

 

[ksc]

at what distance from the fixture to the top of the tank?
I did say it sounds off.

If I remember correctly, about 6-7". A generic t5 fixture will put out about 4-500 at that height and 100 on the sand in that tank.

 

[DracoKat]

the fixture is pretty low to the tank, about 4 inches off the top

whats considered "Generic" Fixture 4 bulbs? I have 4 bulbs