While setting up my rack my Wife decided that she also was interested in adding to her tank. Of course, I am all for this. Happy Wife = Happy Life (and less arguments when I go and spend money LOL) We know from past experience that not using a QT can be a huge risk so we grabbed a 4 pack of 12 liter Sterilight boxes (about 3.5 gallons) and took some old heaters and sponge filters we had laying around to make some standby QT tanks. In the first picture, you can see that we are storing these on the top of my rack for future use and they will not get used for anything else since all the needed supplies are stored inside. In each box we keep a preset heater and the body of a sponge filter. The filter foam is in my wife's tank to keep it seeded. It has been in there for 3 weeks and should be ready to go when needed. If there is a need for chemical filtration a small air driven box filter with carbon etc will be put in there also. once QT is over the sponge can be cleaned (or replaced) and placed back into one of our tanks for seeding again. since we have two of these setups we should have no problems keeping one on standby and one in use. Unless of course she and I get fish at the same time!! Down the road, I intend to have more sponges on reserve in one of my tanks so that the rotation can be made a little simpler.