just to get something going

[jilo]

i have a 90 gal tank, stand, aq 500, fluval 404, (has been cichlid tank), i was thinking about going marine...reef maybe, what would i need to do so, what would i be able to put in it...
k

[OrionGirl]

The filters will be little more than large powerheads--you won't want to run any media, but it's nice to have the option. Best filtration is live rock and a deep sand bed. You'll need about 100-140 lbs of rock--you can use mostly base rock and enough live rock to seed, or use all live rock. Then about 4-6 inches of fine grained sand for the substrate.

For a reef, you'll need to upgrade lights--most corals are photosynthetic, so 4+ watts per gallon (VHO, metal halide or power compact lights) is a must. Fish only, well, you'll want enough light for your viewing pleasure plus a bit--probably more than you had on a cichlid setup.

Otherwise, heater, hydrometer, mixing bucket. Depending on your water source, filtration of some kind might be needed.

For stocking, you'll have quite a few choices. You could have a tang (once the tank is established), clowns, wrasses, eels, etc. It will depend on what you like. My advice is to pick 1 or 2 show case fish, then build around them. Many fish are not reef safe, so you have to go one way or the other--no point adding a coral if it's just going to be a snack for a wrasse. ;)

[mogurnda]

A few additions/comments.
Protein skimmer. Can't forget a top-notch protein skimmer. With a tank that size, an in-sump model would be best, but you might be able to get by with a hang-on unit like a Remora Pro.
Lighting can be a little lower if you want soft corals or large-polyped stonies. 3 wpg will do for them IME.
Refractometer is a really good idea. Most hydrometers are pretty inaccurate, so it's worth it.
Test kits. To start, good NH3, NO2, NO3, pH and alkalinity. Once you get over the stress of the cycle, Ca testing is a must. I prefer Salifert.
My opinion would be to think about what you want to look at. Do you want fish, then just get fish and some good live rock. If it's only fish&live rock, your current lighting will be fine. If you want corals, you might want to start with softies, which are much easier to keep and need less-expensive lighting. If they bore you, then you can spend a lot more money and try your luck with small-polyped stonies. In the case of the corals, just get a few fish to showcase.
Another possibility is to start the way I did. I got a batch of Caribbean live rock, jam-packed with sponges, arks, small corals, macroalgae and other hitchhikers and just enjoy all that for a while. After a year went by I added a few corals, but I think I still like the hitchhikers better.
One place to get started is John Tullock's book Natural Reef Aquariums. He devotes a good bit of the book to the different ways you could have the tank set up, plus it's full of good practical advice.
Dang, that was long. I must be procrastinating, eh?

[kreblak]

With a 90 gallon tank, your fish choices are pretty much limited only by your budget. You will definately need a 4 inch or more sand bed and live rock to the tune of 1.5 pounds per gallon. Like Oriongirl said, you can get base rock, and seed it with the live rock. Just make sure that you have ample hiding spaces, and plenty of caves created in your rock work. This will give the fish lots of places to hide, thus cutting down on territoriality and aggression. More importantly, though, the sand bed and the live rock provide the basis for your biological filter. The bacteria growing there will break down all of the nitrogen compounds excreted by fish, making the water livable.

You will need to cycle the tank prior to adding fish. The best way to do this is to set the tank up, fill it, add the rockwork and any decorations, and let the heater bring up the water temperature. When the temperature is where you want it, then toss in three uncooked jumbo cocktail shrimp (available at your local grocery store) and let them rot. As they decay, they will produce huge quantities of ammonia. Your bacteria base will feed on this ammonia, growing rapidly and converting it into nitrites. The nitrites will then be broken down into nitrates by a second type of bacteria. Nitrates are far less toxic to fish than are ammonia or nitrites. Finally, there is an anarobic bacteria that will grow deep within your sand bed that will break down nitrates. You should test your water while you are cycling to see how it is progressing. Depending on a number of factors, your tank should be cycled in about a month, give or take a couple of weeks. When you can put in a shrimp and not detect ANY ammonia or nitrites, your biofilter is ready to handle fish.

In a 90 gallon tank, you have the swimming space needed for tangs and wrasses, so you can pretty much put in whatever fish you can afford and like. Just be sure not to put in fish that will fight, and don't mix predators and prey if you want to keep the prey alive. If you want a reef set up, then you will definately need some good lighting for your corals and macroalgaes.

Good luck, and welcome to saltwater!

[jilo]

excellent advice from all, which i have come to know as common here(ac and its members have taught me alot). having keep it as a cichlid tank, meaning i had one oscar that didn't let me put anything in the tank, (other than food) besides the common/sailfin pl*co that has been in the tank as long as oscar. i have no problem having one showfish and just filling in around it, i like the idea of having lots of reef/coral, lights are not a problem (ill get whatever is nescesary). i would like to to add lots of corals/reef to eliminate filtration systems (except for the protein skimmer). so budget not being a major concern for lighting and stocking, what do you all have for sugestions as far as a showfish. at one point i remember seeing some triggers(spelling?) that looked interesting, any comments? i think i forgot before but thanks to all for your very valuable help.
k

[OrionGirl]

Triggers are great fish, with personalities on par with many larger cichlids. Great colors, many varieties, and readily available. The problem? They make snacks of corals. Not a reef safe fish, in anyone's book. There are a few that will be okay for a while, but triggers are well known for thier overnight behavior and temperment changes--you go to bed, and wake up to borken rocks, shredded corals, and dead fish (depending on the species).

You have the room for a single trigger (though you can pick from several species), but you'll have to choose between a trigger, or a reef. This is the reason that most of us end up with multiple tanks. ;)

[kreblak]

Triggers make wonderful showfish, but Oriongirl is right on the money, they love to chew on rocks and corals. It is also possible that they'll go after other fish in the tank. Monosebealover is the resident trigger expert, I think she has one or two of every type there is! Personally, I think the Undulated and Niger triggerfish are the best looking.

As for other showfish, you could get a large angelfish, a tang, or something exotic like a Panther Grouper or an Emperor Snapper. Check out www.liveaquaria.com and take a look at what they have to offer. They are affiliated with Drs. Foster and Smith, who are excellent.

[mogurnda]

Triggers are relatively undemanding, really fun, but destructive. Niger triggers are less so, but I still wouldn't trust them with any inverts you care about.
The other issue is that they are messy eaters, requiring more mechanical filtration and attention to water quality than many other marine fish. Like a marine oscar, in a way.
Another possibility might be a dogface puffer. They are also relatively easy to keep, and can be very tame, but aren't such terrors.