How much light do I need?

[Mattt]

2 weeks ago I swapped my Prime HD for a new 32HD. Im running David Saxby's settings and I set the 32HD at 50% and to ramp up to 100% over the next 112 days. How do i know if I am overdoing it with the light? This is on my Waterbox 20 cube and the light sits 11in above the water line. This tank has a mix of softies, LPS, and SPS frags.

 

[Pntbll687]

watch the SPS frags for polyp extension, growth, and coloration.

There is so much going on in the tank, it's hard to tell if lighting is actually the culprit or not. I don't know if you need to ever run the light at 100% or not. It does seem like you have allotted adequate time for corals to adjust to the lighting as it ramps up in intensity.

I would think the only way to tell if it's the light is to keep everything else the same while the light ramps up over the next couple of months. That means same water change schedule, same dosing, same everything.

 

[Mattt]

Thanks for the input. I'm confused about the par requirements on some of my frags. My Jedi Mind Trick was recommended to be kept at 250Par but I've heard much lower as well. According to AI the 32HD has a peak Par of 174. I thought I was overdoing it with the light but now I'm concerned I might not have enough. I also have zoas and mushrooms close to the bottom I dont want to fry.

 

[Pntbll687]

250 par has become the blanket answer for almost everything. You can grow coral in much less intense par.

Check out this guy that farms coral in greenhouse with nothing special. He says that 150 par is high and sps will even grow in sub 100 par

As for what your coral needs, just keep monitoring it. It can take a while to get nutrients right in order to get good growth going. Start the coral lower in the tank and move it up if needed.

Don't overthink things and mess with the light settings. You're using the Saxby program for a reason, it has a proven track record of working.

 

[Mattt]

Awesome! Thank you for the help.