I have a storage container and i dont change the water for breeding. Discus put a hormone into the water that cannot be taken out with any filtration. After that hormone builds up it starts to effect your fish. Plus discus come from an area where only clean water flows so there is no ummm i dont know how to say it but basicaly bad water. W/C are actualy really easy i have a pump rigged up so i can drain my tank in 5 minutes and fill it back up in 10 the enitre process only takes about 20 minutes. It is alot of work but totaly worth it.