Moving a 8 banded leporinous

Question
Hi, my question is that I have a 55 gal tank with a 8 band leporinous in it.she is my prize fish I would like to move her in a 12d gal tank that has been set up for weeks the cycling is done.my perameter are the same in both tanks cuz I am using the same tap water with the same declor.solutions.an yes temps r the same in both tanks . My 125 already have gourmis,angels,and rams in the tank all fish are fine. I was wondering do I just net her an place her in the 12d or do I place her in a small tank with a airline that is dipping the 125 gal water into the small tank? She is very shy an stresses easy do to the size she is. She is about 7" long . She is a very picky fish meaning that if I move something in the tank an she don't like it she will move all the rocks around the tank until the plant falls or the driftwood is where she likes it. That is what I mean about stresses easy she likes the tank to be the same all the time. Another question is my 125 has been running for months now an I have never did a water change yet I know it is recommand but all my fish are fine. I have a xp4 rena filter running the tank do I still need to do water changes? Thanks David

Answer
Hi David,
Im not sure what you mean by "12d".  Do you mean by 12" depth?  To try to answer your question, the 7" band leporinous should be in a tank no smaller than a 55 gallon tank.  If she is your most prized fish, I would make sure the water is completely cycled before transfer.  Thats very neat how your fish moves decorations around until she sees fit.  Ive actually never seen or heard about that before and is very interesting.  You must do approximately 15%-20% water changes weekly to reduce nitrates.  All the waste and extra foods will break down into ammonia then to nitrite and finally to nitrate.  With the two sets of bacteria that breaks down ammonia-to-nitrite and nitrite-to-nitrate, there is nothing that breaks down nitrate which must be removed by water changes.  Fish can tolerate nitrates to quite a high level as it is the most less toxic form of nitrogen in the tank.  Your fish will eventually all die if you are not removing nitrates.  Think of it this way, you add food to the tank to feed the fish, and it must come out somehow.  It comes out via water changes.  But a liquid test kit, it should be available at most fish stores.  Fish can tolerate nitrates up to 40ppm but I recommend the lower possible such as 20ppm or less or even 10ppm or less.
-Matt-