Very! Ur cheato will die off if no light. Then there will be not reason for a refugium
When i 1st set up i had the hd light it worked fine.. But switched it out for a cpr light. For a cleaner look. But thats just me im anal..lol
What kind of a fuge dyu have? I've used Ikea dioder LED's with no issues for Chaeto (Will need to be screwed into a hood of some sort. I also use a coralife T5 mini light.
thats not bad that will grow chaeto like mad