I also have a couple of questions for you, as I am seriously thinking of doing this in a couple of weeks.
I'm red!
1. What did you do with the excess clay? Selling?
have about 15lbs of it left. I got it at a craft supply store.
2. I have 2 bags of Clay "like" Flourite planted substrate..Think I ought to just throw it in there as well?
I had flourite previously on this tank. If your going to use clay use that and not the flourite. If your not going to use clay, use the flourite. But IMO Clay seems to work best for people.
3. Did you use Playsand or PFS as your topper?
I used play sand, Home depot in 50lbs bags 1 1/2 should do it for a 75 gallon. WASH THE SAND UNTIL YOU THINK ITS NOT GOING TO CLOUD THE WATER, AND THEN WASH IT 5 MORE TIMES.
4. How long was your ammonia spike, and if using a "SEASONED" filter do you think it would shorten the period some.
After about 3 days, with a seasoned filter, all parameters were back to normal.
If you want to do this VIA PM I am down with that.