I had a 100 Gal about 13yrs ago but had to downsize 13 yrs ago to 55 Gal. It is now well established & planted with multiple plant types having created its own ecosystem. I used playground sand bag bought from Lowes that I used a bucket & water to rinse out all the floating particle sifting the sand by hand as the particles floated out the top with overflowing water. I did the same with a small bag of topsoil I ran the water & Sifted until the water in the bucket was clear. I then drained the bucket & put sand in LG cooking pot & boiled with water on the stove. & after did the same with topsoil. I then put enough water to cover & added Coppersafe to kill off any remaining parasites & let stand a few days & sifting a little to make sure Coppersafe reached everything. I then rinsed out to remove coppersafe because it is harmful to plants. I then put liquid miracle grow & enough water to moisten the soil & packed it into Ice trays & froze solid. I also added miracle grow to sand I diluted down the Miracle Grow being afraid it might be harmful to fish. I had some pea gravel & crushed charcoal too. the tank already had a small layer of sand across the bottom of the tank & had already been established for many years with fish. I then placed the frozen soil cubes into the original layer of bottom sand & then covered all with new sand & pea gravel. so that when soil thawed out it would be held in place by a heavy layer of sand & gravel. I have had for many years now a well established 55 gal tank full of a diversity of plant & fish. I had also placed Old grapevine wood as driftwood & placed LG sandstones I had gathered from different lakes from a few different states. I also have a few small snails & ghost shrimp & had freshwater clams that I gathered from the Kings River in Ca. But they didn't survive the move from Ca. to Ok 13 years ago as most of My fish also died during the move. I am hoping to get some more clams for My tank eventually but the pet stores don't have them & haven't seen them in local rivers yet. I have Lg clown loaches & a couple of Cory cats & a Plecostomus along with a diversity of other fish of different sizes & shapes. I have two Lg dual water overflow pumps but I rarely clean out & I removed the cover to use & a plant holder for My bamboo & to start some plant seeds. I periodically add some crushed charcoal by dumping some into the tank that becomes part of the soil medium. One of My plants grows very vigorously & new starts float & attach to different things & grow on the sandstone & The faux hollow log that is The Clown Loach couples den. That they now seem to squeeze into since She has grown to twice His size but they are snug & happy. I tried adding Large snails to tank but Clown Loaches eat them but haven't seen them eat the tiny snails that have always been there.