Trying to start "low" with LED's but confused

i_declare_bankruptcy · Oct 4, 2018

Hi all I have a 525xl and 3 Kessil 360W's about 6" above the tank. The tank is young, only about 5-6 weeks old but completely cycled. I have the controller set to ramp the lights up to 20% intensity, 50% color for 10 hours. I'm just wondering if I'm starting too low -- my corals look fine save for a temperamental leather and a couple that were damaged in a lighting transition. Otherwise they all completely come out (and occasionally shrink up during the day but that's normal right?). It does seem like a couple corals (toadstool and one of my hammers) are "reaching" for the light.

I guess I want to be sure that I'm not going to see any negative effects from starting low -- definitely didn't want to start high haha.

ihavecrabs · Oct 4, 2018

It sounds as if the PAR you are starting out is pretty low, but for softies, it'll be fine. The hammer might get a little upset with the low light though.

From what I saw with a quick google search with the light 8" above the surface:

6" below the water:

Center 12" x 12" average is 188 PAR
next 6" out is 60-100 PAR
next 6" out is 10-50 PAR

12" below the water

Center 12" x 12" average is 103 PAR
next 6" out is 60-80 PAR
next 6" out is 40-60 PAR

18" below the water

Center 12" x 12" average is 65-70 PAR
next 6" out is 65-70 PAR
next 6" out is 60-65 PAR

Keep it mind, as you have more than one fixture that overlapping coverage will increase the PAR in those areas. Interestingly enough, you'll find that the spot in-between your fixtures may be the highest PAR.

jda · Oct 4, 2018

Kessil are not output monsters. I would get those up to 50%, or more, over the next 10-14 days. Only a PAR meter can really tell you where you are at, but there are PAR maps from BRS using those lights that can give you a rough idea. I would try and be over 100 for most corals, but lower than that in the shadows works ok for some softies and even some LPS.

If your corals are reaching, then they are speaking to you and telling you that they want more light.

Corals should not shrivel up during the light cycle unless they were irritated by a fish, or something.

i_declare_bankruptcy · Oct 4, 2018

So I originally started at 50-60% (originally based off the charts you just suggested @jda ) but was told to back down by a few people on here so I did out of fear of bleaching my corals. I only have softies and LPS right now (for the foreseeable future).

I think I'll slowly start increasing intensity.

I noticed mainly my duncan frag (on the sand bed) and my tempermental finger leather are the ones that close up periodically. I think the duncan might just be getting too much flow and the leather not enough light to be honest. All other LPS and softies are doing fine, not that there are many in the new tank.