Build my 120G tank from the ground up!

Are you wanting this to be a FW or a SW tank?

Well I guess if it were my tank I would want to have it planted with lots of drift wood. That would probably mean something liek flourite on the bottom for great plant growth. I would lean towards a large school of dwarf cory catfish, at least 10-15 of the guys. They are awsome to watch in large groups. Then I would put in a school of smaller tetras, which should be able to adapt to that pH fine, though they probably wouldn't be able to breed in it. Maybe 20 or so small tetras. Put in some fresh water shrimp and snails for cleaning things up. Put in a smaller pleco and a school of ottos (6-8). I say smaller pleco cause I like to keep my fish in a similar scale in size. And I would have some dwarf gouramis as well. Now I prefer lightly stocked tanks and wouldn't want too much in it excpet many plants. I am sure that you can probably stick way more fish in there. Perhaps some platies or swordtails for colour as well. And everytime you look into the tank I am sure there will be a new surprise with lots of baby platies.

Okay...Just wanted to make sure!

For a FW tank....Hmmm. I am a big fan of planted tanks, and for something that deep, you'll probably need to have good lights--power compacts, probably I would get 2 of these: http://hellolights.com/484xcofraq4x.html since that gives you about 4 watts per gallon. This will allow you to have most plants without problems. MH might be a better choice, to address the depth of the tank, but I think the PC are easier to deal with and will be a good choice. Plus, if you later decide to go SW, you're half way to having the equipment for a reef.

For fish...This is where it gets a bit fuzzy. Many of the fish that meet your description are sensitive, and can be hard to keep--not ideal for a first timer. Some stunning discus for example--but they require good water conditions, and stability, so shouldn't be the first thing in your tank. With most fish, you can get TB fish that wil be fairly hardy, but common, while something like a wild-caught scalare angel is going to be demanding as well as rare.

What I would put in a 120: 5-7 bristlenose plecos. Good for cleanup, will probably breed, attractive color pattern and not all of them will hide.

7-9 otos--clean up, help out the bristlenose without competing for caves.

7-9 rainbows. Partial to the iranian reds--striking color, non-typical shape, community fish.

Pair/trio of apistos. Several nice colors out there--something bright, yellows or blues.

A bunch of shrimp--amanos, bumble bee, or, if you really want to spend the money, the crystals.


I really prefer tanks where seeing the fish is special--not where there are so many fish that you always see them, but enough fish that if I take the time to look around, I see them.

To me, anything that is more than 18 inches is a deep tank, and the larger tanks all tend to be deeper than that.

For substrate--flourite is your best choice. For a moderately planted tank, I would use a mix of flourite and a small grained gravel to help reduce cost.

I like a mix of plants. If you add driftwood, anubias is an excellent choice, easy grower, and they will bloom regularly. Combomba is a good choice, but does better in slightly cooler temps; 68-72 is best IMO, but it will grow in warmer tanks as well. A variety of rotala to choose from; I like rotala indica best, with it's small leaves, and red tinge on the upper levels. A few swords would be nice as well--some types get huge, but a 120 has the room for this. For ground cover, I would go with crypts--they will spread well, and provide low cover that fish will enjoy playing in. The fish I listed will all be fine with most types of plants. The otos and bristlenose will collectively be able to clean both the broad and fine leaved plants, as well.

For equipment--I would seriously consider setting up a wet-dry with a sump. You can hide the heaters and such down there, and you may need to use supplemental CO2, so that could be stashed in the sump as well. A surface return bar with slow movement will prevent gas off, and the trickle through the filter will encourage oxygenation of the water leaving the tank. Other optins--canisters are probably going to be your best bet. Few HOB can handle that big a tank. I'd even go with a pair of them, one on each end.

You'll probably also need a few powerheads to provide for some internal movement. Filter returns can be adjusted, so the water can come in at any level, but a few powerheads will really help prevent dead spots where detritus collects.

Heaters--go with 2 500 Watt heaters. This way, it won't run all the time, but it won't fry the tank if one malfunctions. I really am happy with my ebo jagers.

I'm really bad at brands--sorry! Run some searches, and I'm sure you can find some good names.

For a sump, you need just one pump--the return. You can use an overflow to get the water out of the tank and gravity will pull it to the sump. The return pump just needs to have a valve after it, so you can control the rate and make sure the same amount of water coming out goes back it.