After 3 1/2 years, this tank needed some serious rejuvenation. The weekly hacking back didn't make it look much better, the substrate (pea gravel over loam) got very hard to plant in. Adding the Festivums back when wasn't a great decision, both for their plant-shredding abilities and the fact that cleaner-uppers such as shrimps had no chance in this tank.
So, after slowly moving the big fishies into their new home, the day came to get it all out and empty. I took a day off and sent the family far away... things always happen and a youngster running around asking what that fish is doing on the carpet is just not helpful... okay maybe it would.
I used pretty much the same recipe of substrate as in my 36gal and 55gal tanks - first a nice thick layer of previously soaked peat, none of this thin dusting stuff for me, thanks.
As you can see, I didn't really squeeky clean the tank, there is a remainder of the muddy loam left over which is soaked up some by the peat. Add a secret number of jobes sticks and push them all the way to the bottom of the tank, as an initial fertilizer seeding.
I spent some time figuring out how to arrange that big piece of wood in my tank. Before, it layed straight, but looked weird, now I moved it kind of weird with rocks underneath it and such, but it looks much more natural.
Next, I used two 25lb bags of Special Kitty ($2.22 ea), which in my case contain fired clay, texture very close to Flourite, just a tad lighter. On top of that I added some Flourite straight out of two bags, no washing for me, thank you. Mainly I used the Flourite because I had them from back when I bought them at $6 per bag, labeled as "gravel vac", and I couldn't convince the Petsm@rties otherwise. Also, being a little heavier than the Kitty stuff it makes planting certain plants easier.
STOP... I forgot something. At this point I should have cleaned a nasty canister filter, and used all the bio-sludge to seed the substrate. I totally forgot... oh well.
Now here is 50% of making the substrate-not-rinsing work: before doing anything else, siphon out all the water that is in the tank (from wet substrate, cleaning windows, spraying any plants that might start to wilt, etc). That moves most of the fine goodies down into the lower substrate layers.
The second part for success is to add the water very, very slowly, and even then, make sure there is no water movement whatsoever. Sponges work good. It's a little tempting to fill that sucker, but remember, going slow will be a guarantee for clarity later on.
As the tank fills, planting starts... there are little dust devils as you push plants down into the new substrate, and overall water clarity is going to heck, but no problem, a few hours later it will look better, and once the tank is 60% full, filters can get started, making sure the outflow does NOT point towards the substrate, of course.
All in all it took me the better of one day to redo the 100 gallons, the next day was still used to finish planting, and clean up...
So right now the fauna - a Flying Fox which I bought 3.5 years ago when I originally set up the tank, 3 Yoyos that have been there a few years, and my old pair of African Butterflies which moved around since the Festivums started ripping out their fins. Also two Otos that have been there since the beginning of the tank. New: a whole bunch of Cherries and Amano Shrimpses, plus two starved Otos saved from Petsmt today. Thanks to the XPs the water is crystal clear, and the whole thing is a pleasure to look at.