Laterite Vs Flourite

[`Peter]

Whats the difference in each? Which one would be better to combine with gravel in a planted tank thats been cycled for about a month now. Can I still add this now even though I have fish after I rinse it?

 

[SO19Firearms]

If you can find out - Which ever has the higher CEC value is better IMO
You can add either after, but any mess/cloudyness will be the problem.