should i    
By fishboy123

Please look at my latter comments in that list. The idea is to get both filters effectively functioning.  You can also bring gravel, rocks and plants over from the other tank. You may not get a new one set up ASAP, but you will get it done correctly.

Having said that, I picked up two pairs of fish at a show this weekend. Each animal is separately bagged so they will be safe overnight (the water in them is pretty clean because the fish were not fed for a day or two prior to packing and they had nothing to regurgitate or pass.) I will be taking 60% of their water, gravel and plants from established tanks. By evening they will be comfortably escounced in their tanks. I probably will not bother with a filter - yet. They will get a modest feeding of a live food (Daphnia) which will swim around with them until consumed - there will be nothing to decay in the tank bottom.

When their tank is set up, the fish will have their bags poured into a jar. (Actually they will be separated into four small pickle jars, because they can panic and injure one another.) The jars will be closely covered because they are fabulous jumpers. Their water will be poured off or decanted until they are in an inch of water. A similar amount of water from the tank will be added. About 20 minutes some of the water will be poured off again (into the bucket that gets dumped in the garden). I'll do a third pour off and adddition of water to the jars. After an hour (or if I get on the computer, two hours) ALL of the water will be poured into the bucket and the fish gently placed in their new home.

Those purchases come from a Michigan aquarist who probably takes better care of his tanks than I do. Still, why risk introducing any more disease organisms or algae spores from his tank (or a pet shop's tank for many purchases) than I have to? And with the gradual change, they will be adjusted to any differences in the chemestry of the water.

Please note that 60% of their water in the new tank does not mean that the tank needs to be full. It must be well covered, considering the nature of the fish. Who says a new tank must be full? The tank might be only half full at the moment. It can be gradually filled as time passes. :)

Room temperature (I did close the windows last night) in the midwestern U.S. is still usually safe for the fish. When the tank is full, you can put a heater in that aquarium. (I cheat and heat the room. That may be cheaper if one has several tanks.)

Another thing about that new tank. The fish mass and population will be very small. Either one or two pairs of quite young killifish (Fundulopanchax scheeli) will be put in a ten gallon tank. Each slim fish is slightly under 1" in length. That is another necessary trick involved with establishing new aquaria.