Lighting Question

[Mabyboi]

Hi guys,

I have a 24 Gallon cube, with a mix of LPS, SPS and a bubble tip anemone. Only inhabitants are two clownfish, a goby, and a blenny.

I would like to have my tank lights set to be on for 8 hours, which are a mix of white and blue LED's, and have 1 hour of Blue Light/Moonlight before and after, to make it a total of 10 hours.

What wattage is required to have a light that will stimulate corals for for the first and 10th hour? Not full blown stimulation like the daylight lights, but not so little that it will do nothing?

There are some eBay strips that are 1W each, for 12 or so LED's, and there are some from BIG A's, that have 72x 0.06watt LED's.

Looking for advice!

Thanks!

 

[OceanRevive]

It's nearly impossible to determine by using wattage as a measurement. You need to use PAR (Photo-synthetically Active Radiation) as a measurement of the available light. Watts is about electricity and every light fixture is different.

I think most corals zooxanthellae will be active at a PAR of about 100-200 or more. There is some research out there that says coral zooxanthellae is only doing photosynthesis for a limited time frame of 4 to 6 hours anyway and then it shuts down. Other scientists disagree. But with your blue and white leds on for 8 hours, you really aren't going to gain anything with dimmer blues before and after the 8 hour photo period. That's really more for your eyes and not for the good of the coral.

A good follow up question, which I don't know the answer to would be: Is photosynthesis more like an on/off switch or a dimmer switch. Does it 'turn on' when there is enough light and 'turn off' then there isn't enough light? Or does it ramp up and down as the available light (PAR) goes up and down through the rise and setting of the sun? I'm not a biologist, so I don't know the answer. But I'd like to find out.