I lightly siphoned the top of the sandbed and rock when I cycled my tank to get the die-off out, but once established I stopped. I have had plenty of FW and SW is a little different in some ways as far as maintainance to maintain water quality. The live sand and live rock are biological filters and breaks down waste and uses nutrients. The nitrogen "Cycle" is the breakdown from Ammonia then to Nitrite, and finally Nitrate. Bioload is another term you need to know, if the load is too great(too many fish, overfeeding) your biological filter can't compete w/ it and your water quality will go downhill quickly and livestock will suffer if not perish(less tolerate than FW), if not corrected fast. You still have to scrape algae now and again and water changes cannot be neglected. I test my water regularly, at least once a week. Get some books, read the archives on this board and others. Goggle it. The point is read until you feel comfortable to take the plunge. Then keep reading to overcome anything that might arise. I jumped in with both feet and started a Reef, Fish Only tanks are a little easier, but same basic rules still apply. Know the requirements for long term success and your halfway to achieving it. Hope this helped.