I hope you find one, but if you don't,
don't go without a light meter!
Use a [HASHTAG]#lux[/HASHTAG] [HASHTAG]#meter[/HASHTAG].
You can get a freebie for your smartphone's camera (like "galactica luxmeter" for iPhone) - which is a great way to start.
If you can wait for free shipping, a $15 handheld lux meter is an excellent investment. The "lx-1010b" is the model than
amazon, ebay and all sell... Several of us use this one or one nearly identical. It is good. Take measurements at the water surface. :D
If you click the tags above and read through some other recent threads, someone else mentioned a model with a waterproof sensor that was around $50 in case measuring underwater is a "curiosity itch" that you just gotta scratch. :p You can definitely make-do with measurements at the surface though!
There are simple conversions from PAR to lux (and back) that are accurate enough if you have some PAR numbers you are trying to work with.
Working in lux is perfectly acceptable too.
For reference: "Direct sunlight" at sea level = 2000 PAR = 100,000 lux = 1000 watts per square meter
Around 40,000-50,000 lux (1000 PAR) at the water surface makes for a pretty well-lit tank in most cases.
For what it's worth, I have two SPS tanks - one has a peak of about 40,000 lux and the other about 15,000 lux. More light is not better. ;)
BTW, what's going on with your coral? New lighting?
