Ines Scheurmann, a prolific writer who has several books out with Barrons, has noted that difference. She claims that water at 32 degrees F/ 0 C has twice the oxygen of water at 86 degrees F/ 30 C.

By the way, if your goldfish were to drop to 55 F or below, you probably wouldn't want to feed them anything. Their metabolism drops way off. Food can actually rot in the gut of coldwater fish whose water drops in temperature so fast that they haven't processes it. Some good news, if you have a heater on that 55 gallon tank, unplug it and save it for another day. You've saved a little on electricity.

You mentioned the marking on one of your new goldfish has some black on it. If they are only about three inches long, you could be in for some entertainment in that colors (colours) tend to come and go before settling into their adult pattern. Maybe they're just bored. I'm enjoying your accounts of their social behavior.

Smart move dumping that tetra. If your friend is going to try a school of neons with him, he may want to get several other "firetails" right after the neons. Sometimes an aggressive fish is better behaved in a school. I've heard 6 fish. My friend Ines, suggests 7-9 tetras for starters. And take a look at the Japanese planted tank artist Amano and his schools of small fishes!

In the case of that most beautiful but scrappy tiger barb, schools become them. On the one hand, they are more "comfortable" with others of their species. On the other hand, they are reluctant to attack others, because they are busy watching to see that nobody else takes a shot at their tail. :)

I'm Sorry about the siphon injury. Those things happen. I've actually turned the radio off or turned it to a dull station (a noise  barrier) so as not to be distracted.

Just before lights out tonight, a Fundulus catenatus spit out a small shrimp pellet, which sang (pardon me, sank, I've got a cold) under a tangle of Java moss. They have been surprisingly fussy feeders and unwilling to follow many foods to the tank bottom. (Maybe, as North American fishes, they feel there is a North American catfish "down there.)  Muttering to myself. I really quickly grabbed a bucket and siphon. Didn't want that b.s. pellet rotting down there. (Can you say velvet outbreak?) Can dump the water down the privy in the morning and leave the bucket outside to freeze whatever is growing in there.