My 100w light on a 15g cube.

[Knucker]

I set the light to LPS on the settings. This has everything at 80%. I felt that was too bright so I turned it all down to 20%. I still feel it might be too bright.

My idea is to start off at 10% and to turn it up 1% each day until it's back to 20%. Then wait a couple of weeks then slowly turn it up to 40%.

My question is this a slow enough light acclimation?

 

[Hooz]

Depends on what you're keeping in the tank. I have an IM Nuvo 10 full of BTAs and RFAs. I use a Hydra 26HD (95w) light on it and have it set to about 30% (based on my color mix).

The human eye is notoriously bad at guessing light intensity for this kind of thing. The only way to know for sure is to get your hands on a PAR meter and test your light on your tank.

As for acclimation... If/when I use an acclimation mode, I try to not raise it more than 5% per week.