Eli,

Any concerns with running Carbon and HC-GFO from day 1 of curing the rock in the tank? Or should I wait before adding those 2 online?

There really is no issues running them from days one except it's a waste of money in my opinion.

Heater failed...
 

I tried to do the same thing for my dry rocks, everything was going well but after 7 days last night my heater holder failed, heater went into the water and thermostat failed! Finally temperture went up to 90 For 4-5 hours

Now what? Should I start everything again? I ordered a new submersible heater.

I wouldnt worry about it IMHO, if you have nothing in there you arent going to hurt anything. just think of it as a very hot day and the tide was out in shallow water.