cycling SW aquarium with shrimp???

Alright, lessee what I can do here. Yes, the shrimp cyclin' method does work. I've done it. If you already have live rock and sand, I wouldn't bother with the shrimp. The high nitrite levels will kill off alot of good stuff in the rock. I'd only put the live rock in first if it's uncured, like if you ordered it online. If you have a filter, I'd just run it empty and just use it without any media in there. Otherwise stuff tends to clog up really quickly, thus raising your nitrate levels without frequent maintenance. Any raw or frozen shrimp works just fine. Two should set ya good. Within two weeks, your water should be raging with ammonia, and then you can turn on your skimmer, so I'd say wait 10-14 days before you turn it on. Otherwise the ammonia may get skimmed and your cycle will be a poor one at best. During this though the tank should still be heated and have some water movement. If you do plan on adding live sand eventually, I'd add a majority of the dead stuff right away and just put in a few pounds. This'll get the bed going more-so than just the shrimp, and by the time you put it in there the regular sand will long have settled. Sorry if this was pretty erratic, but I hope it helps.

Yep, the shrimp work. For 50 gallons, two ought to be fine, and yes, you just go to the grocery store and pick up a couple of dead, uncooked cocktail shrimp, and then drop them in. As they decompose, they release ammonia in massive quantities, which kick starts your nitrogen cycle. To answer your "how long" question, you do it for as long as it takes to get your ammonia and nitrite readings down to zero. This usually takes anywhere from 3 to 6 weeks, depending on how oxygenated your water is and several other factors. Then, add fish. There shouldn't be any ammonia spikes associated with adding the new fish, and they ought to do just fine. Get a water test kit so you'll know when your water is okay. Using cocktail shrimp is much more humane (and financially sound) than using damsels which die off at a rate of about 50% during cycling IME.

You can cycle your tank with live rock if you plan on using a good amount of live rock from the beginning. For instance, if you start the tank with 1 to 1.5 lbs of uncured live rock, the die off from the live rock will be enough to cycle your tank. If you start your tank with this amount of cured live rock, chanes are that you will not see a cycle but that amount of cured live rock will provide enough bacteria to begin stocking your tank slowly. .
If you go the cured live rock route, I would still leave the tank fishless for a couple of weeks to make sure you experience no die off from the rock. Then if your ammonia and nitrites are at 0, you can begin adding fish at a rate of 1 every 1 to 2 weeks.
If you plan on starting your tank with mostly dead base rock, I would use the shrimp method and then add whatever amount of cured live rock after the tank has cycled.
I also would not add any "true" live sand until your sure the cycle is complete (no ammonia or nitrites).

Brian

i had cycled my tank with 55 lbs of lr i got off the internet, was pretty bad smelling when i got it. but you would be surprised what survives the cycle and what comes back when it does die it just takes some time. i had cleaned some of the stuff off because it was just soooo nasty and it all grew back. then i added some fresh stuff later on after i had everything going good. which added more variety

and i have a 20g quarenteen tank set up that i cycled with shrimp just throw it in there and let it go the shrimp will dissapear no need to fish it out later