Lighting help

[cheesy]

Hi everyone, I’ve just bought a Redsea reef LED 90 for my 20 cube mixed reef tank off market place they listed it as a 50 but when I got it home I realised it was a 90. Anyways I’m new to the saltwater side and have had success with my few corals with the light that came with the tank but it stopped working so I have now bought this and want to know what settings I should have it at for the overall health and growth of my corals. I assume I’d want to turn the lighting down a fair bit as I assume the 90 is severely overkill for a 20 cube? Any advice is much appreciated as I just want to do what’s best for my tank

 

[Gumbies R Us]

I would definitely lower the overall intensity of the 90. Usually, the 20g, as you said, comes with the 50. I would try and mimmick the settings of a Rl50 setup, but with overall lower intensity

 

[cheesy]

Thank you I’ve got the intensity set 30% blue 3% white and 15% moon with ramp up and ramp down periods. Is this still to high or even to low? I found my corals but especially my hammer has responded well as I had it set to 50% blue but felt it was to high and they were kinda retracting.

 

[Mebbid]

Eyeballing the par is gonna be a crapshoot, especially with something as intense as that light. A par meter would be best, failing that a watt meter can work.

I haven't tried it yet personally, but there's a phone app called photone that can measure par with a reasonably close degree of accuracy.

With a watt meter, id try to tune it to maybe 60 watts and then go up from there depending on how corals react. 2.75 watts per gallon can give roughly sps level lighting.

 

[cheesy]

Rightio I’ll get on to someone about borrowing a PAR meter if I can’t I’ll try that app out. Thank you so much for the recommendations