Ideally I would wait until nitrites go to 0 and nitrates start building up (I assume you already went through the ammonia spike), then just do water changes when the nitrates go past 20 or so to protect the fish. Clownfish are hardy but exposure to nitrites and high nitrates can cause stress that leads to disease. I am not too sure about running a skimmer during the final steps of a cycle, but I think once you have only nitrates it's fine. I would personally not even turn on the lights after getting the clowns and just let the tank bacteria mature more. The ambient light from the room is enough for the clownfish to see. I ran my tank for 2 months with no lights and added microbacter 7 then microbacter clean to create biodiversity and once I turned the lights on I bypassed the ugly stage for the most part. I had a tiny diatom bloom but the biofilm I grew on my rock was established enough to keep the rest at bay. I'm a big fan of taking your time to let things mature because it makes it so much easier in the long run. Especially with such a big tank it would be better to go slow and let the biofilm mature without light. I also used dry macro rock though so if you have live rock it may go faster.
