I did a 15-20% water change over the past two days and now my temp is at 73. Is this really dangerous for my fish? I let the water sit in the same room as the tank for a day or so before I added it but the temp in the tank still dropped quite dramatically. Is there any simple (or even not so simple) way to bring the water to the same temp as the water in my tank, or will my fish just have to deal with drastic changes in temp whenever I do a water change. hmm what else. Oh yeah I guess I should tell you guys the temp before the water change. I try to keep the temp in the tank at 78. Is it a good idea to do water changes over a couple of days? this seems like it would decrease the effects on the fish. thanks