LED Lighting

I was looking online at some LED lights (http://www.aquaholicsonline.com.au/beamswork-ea-60-led-aquarium-light-60cm-2ft-moonlight-10-000k.html), would these work for a marine aquarium? Also, what is the difference between these, and expensive ones normally used?

Hard to say for sure mate but with no fan cooling, small diodes and no idea of optics I wouldn’t use it.
Diodes are made up of ultra thin wafers with toxins/impurities imbed in each layer, they give the white light colours.
Then this is set in resin then a positive wire to one side of those wafers and negative out, that is a diode.
They are set onto cooling material like aluminium to take away the heat produced.
Leds are very low voltage like 20 volts so they need a driver/transformer.
Then a cone is sat over them that is the lights beam director called optics, just like a small torch bulb reflector on each diode.
Heat destroys the impurities so the leds are eventually useless for symbiotic life, but if kept cool they last 10 to 20 years of 12 to 14 hours a day of use.
They don’t have to be expensive, my fitting was $125 to my door from china and it has high quality diodes and a great fitting.
Dual fan cooled
3 watt diodes
80 degree optics
Mostly cool white and standard blue diodes
A few true green diodes
A few red/orange diodes
A few royal blue diodes ‘
A few cyan diodes
A few violet diodes
More reading
https://southeastqueenslandm.aforumfree.com/t940-led-lighting-for-reef-aquariums-tried-and-tested-information-and-what-are-they?highlight=Led+lighting

Thanks for the info.