A busy summer!

If you rinse something in hot water, there is still a chance of a residual even after leaving gear in the sun. Summer sun for a couple of days in the heat is more effective than the bleak weather of November too. If you have a sensitive sence of smell, it may be in the case of a plain tank that your nose knows ...

Bleached some lava rock, did a quick soak (one day each) in both barrels, left it in the sun for a couple of days and had to verrrry quickly get some gasping cichlids out of a tank. It turns out that lava rock is really porous and retained some bleach and leached it out in the new tank. Duh!

(Clean, non-bleach hiding lava pebbles are actually a good filter medium.)

An extreme example, but if there is another opportunity to burn algae off of lava, the lava will sit in the bleach a couple of days and in the thiosulphate solution for August! I think I'll thrash it around every couple of days, when ever I need therapy for frustration. (Kind of a guy thing and safer than chopping wood.) ;)

You are right in wondering about residual vinegar. A tiny bit is not a problem, but isn't vinegar sugar/carbohydrates gone bad, er fermented? One doesn't want an acid plunge in the tank. Also, you don't want the extra "food" for bacteria in the tank.

(Actually at a pH too low for guppies, acid water can kill off most bacteria. That is why archaeologists find whole bodies of 3,000 year old people who fell into peat bogs.)

Perhaps they weren't that old at the time. ;)

Um, I hope you're not reading this right after dinner.

The bacteria, like all organics and some other stuff (germs, parasites, rogue algae, grunge, even some calcium creep) should be burned off = oxidized. You are correct, you will have to start the tank all over again with a light fish load and by adding water, gravel & a sponge filter from an established tank, and then adding plants, etc, etc.   A pair of guppies in a ten is not a bad thing though. :)

Your implied question is, "do I really want to use bleach?" You will answer it for yourself when something is so dirty and or diseased that "nuking" that item/tank seems justified and is about the only option short of tossing the whole mess in the garbage.

The last tank in the bleach this fall was one which I fear had an outbreak of of a pretty virulent fish tuberculosis. While it could have been one of a couple of species of mycobacteria (and different from the mycobacteria species causing human t.b.) rarely people can get "fish-keeper's finger" from it. It is not always easy to get rid of.

The tank had seen everyone die in it. I had just covered it up and slid it in a corner until the gravel could be treated and tossed and the tank nuked. (It was over a year ago that disaster happened.) I didn't want that bug in another tank.

When everything was "in the can" I scrubbed my hands and lower arms in the bleach. After the hot water and vinegar wash down, it was in the shower to soap down again. Clothing was ready for the wash anyway and deposited in the washer. (Nobody else was home - whew.)

I hope you don't have occasion to use bleach, It's nice to know it "is there" if you need to use it though.

All the best,
Scott

P.S :
For more on fish T.B. see
http://members.optushome.com.au/chelmon/Myco.htm  

For some reason rainbows seem particularly vulnerable to that malady and I think I brought that strain in with some gorgeous rainbows raised by a couple who are very skilled aquarists and purchased at auction. (The rainbows, that is...) Even quarrantine didn't stop it from getting carried to another tank on hands or a siphon tube.