Just a little trick I learnt, a day before your ready to add more biopellets, soak them in your rodi water and they won't float to the top. Ruble looks good, I used to use a fishies reactor but eventually just kept clogging. Goodluck!
I have been using pellets for over 2 years on my 100gal mixed reef. I only run 1/3 of a cup of pellets in a recirculating reactor. My experience is you will starve your corals with that many pellets in your reactor unless you feed a lot.
Speed is fine. Tap the top of the reactor to drop the pellets. I never soaked mine and never once had a problem....I spun mine much faster without issue...good luck