I used the live rock from my 32g biocube and some siporax to seed my 110g rs 425xl tank. I didn't have any issues at all doing it this way. I don't think you need a ton of live rock to seed your tank. Just needs to be in a higher flow area like the sump so it can disperse nicely. I think 15% live rock with dry sand and a few different types of bottled bacteria dosed about once a week. I prefer Petco Microbe lift special blend and Tropic marin nitrobiotic. Dose the bacteria onto your filter/bubletrap sponge right before your return chamber! Don't forget your bacteria needs stuff to live so you will need fish or a carbon source to help it thrive.
