BTW: there are two types of ammonia measurements.  Ammonia exists in two forms, "Free ammonia" (NH3) and ionic ammonia (NH4+).  Free ammonia is a dissolved gas, while ionic ammonia is part of a chemical molecule with other ions.  Free ammonia is extremely toxic compared to ionic ammonia.  Ionic ammonia is not toxic, but it won't stay in entirely in ionic form.. read on.

There is a relationship between pH, temperature and and the free vs ionic ammonia levels.  The higher the pH, the ionic form tends to shift into 'free' form.  Thus a simple pH shift can convert a tolerable ionic ammonia level into a lethal one in the blink of an eye.

Most tests that you get in stores measure ionic ammonia.  Seachem's tests will tell you both, and the 'ammonia alert' is a gas diffusion test that measures 'free ammonia' directly since that is the one you're really scared of.

To be clear, you can have two tanks that test the same levels on the 'total ammonia' scales, and yet one can be tolerable to fish, while the other can be absolutely lethal.

I've found this out the hard way.  Our tap water pH is 9.2, and that tends to cause relatively low levels of ionic ammonia to change state to free ammonia.  Doing a large partial water change has killed my fish!!!  (I did a 50% change, and when I came back 30 minutes later the ammonia alert was dark purple and the fish were dead).  My test tube kit showed nothing particularly bad.

According to this: http://ce.ecn.purdue.edu/~piwc/w3-research/free-ammonia/nh3.html a pH increase of 1 point will cause the free ammonia equilibriuum ratio to increase 10-fold.  (hardly suprising given that the 1 point is a 10-fold increase in alkalinity as well).

Anyway, this experience and other factors finally forced me into building an auto water changer so that I can now automatically do two 5% water changes every day, without fail.  My problematic murkey tanks all cleared up, my unexplained fish deaths have reduced, and unfortunately my population explosion has become much worse.

Incidently, this equilibrium ratio is what ammonia detox chemicals try to mess up.  They introduce another ion to the solution that binds so darn tightly to the ionic ammonia ions that very little 'free ammonia' forms.

Also, this is why the two-chemical test-tube ammonia tests use two chemicals.  One is the indicator, the second is a strong alkaline chemical.  The second one causes the pH of the test tube solution to increase well beyond pH 12 in order to force all the ionic ammonia to convert to 'free' ammonia for measuring.  But here's the trick, the indicator agents in the new tests (yellow through green) bind less strongly to ammonia ions than the 'tetox' chemicals do.  As a result, they dont 'see' the "detoxified" ammonia.  So what "Amquel Plus" and "Ammo lock" are doing is introducing a chemical that holds onto ammonia so tightly that it has very little chance of converting into free ammonia, and so tight that even the new-style ammonia tests won't see it.  And since it can't convert to free ammonia, it can't poison your fish.

This is why you should avoid ammonia detox chemicals during tank cycling.  The extremely tight binding makes it very difficult for the bacteria to break it down.  If it doesn't cause it to starve and die, it will certainly slow its growth   You really don't want it in there.  In my opinion, steer clear of 'ammo lock' (and to a lesser degree, 'amquel plus') type chemicals during cycling.

Because of redecorating elsewhere in the house, the fish were vacated from a 55 and a 40-gallon tank. Those fish are in a 40 gallon rubber maid storage container and a 32 gallon trash barrel (long ago dedicated to fishy things). The barrel of rainbows also has it's own powerhead and sponge filter. The residents seem happy and hungry at 68 degrees F/ 20C.

If there were guppies being held in a container like that, it would be placed on styrofoam for insulation and an Ebo-Jaeger submersible heater would be installed. I would rather not take them below 75-6 F/ 24 C.

Those two containers, in the middle of the floor, sure alter the foot traffic pattern. Try tippy-toeing around them while holding a 1/3 full, graveled ten-gallon tank. ;)

Rainbows need space, lots of oxygen and current and they, none too soon, got plunked into a ten-gallon tank. The schnoodle and I will run out this morning for one of those small submerged canister filters (essentially an enclosed sponge filter with a current) for their tank. Have an extra powerhead, but that would be too much for a 10-gal/40 L tank. We want rainbows in a current, not flying fish. :)

One of them is a bit clamped with a little fin damage. Maybe, for the first time, will try Melafix (as per Maggie's recommendations). If it is a bacterial problem, it can be healed. If it is fish TB, that will be trouble. (Goodbye! Goodbye!)

The killifish were wonderfully robust and had been very well fed at the LFS. That has been a part of the problem. Even after two water changes, they kept regurgitating food and/or passing it through their digestive tract. The water keeps getting really funky.

I'm not even pretending that the bowls are cycled. Either daily or every second day, they are getting roughly a 95% water change. The water is decanted so as much as possible can be poured into a "out" bucket without losing the fish. About 70% of that new water is from my "start up tank," the rest from the 50 gallon (food quality) "seasoning" barrel.

Because the frequently changed water is all from the same sources, acclimation for chemical differences is not an issue. (I know a couple big time breeders who run daily 95% water changes on their tanks. The water comes heated, run through a carbon-block filter, to the tanks. One can only make changes on that scale if they are consistent. If water changes are missed for a couple of days, then they must back the changes down to 25-45% or mess up the fish.

Those fish have not been fed this week and will not be, until Sunday night or Monday AM. (We may return through one of those famous snowstorms blowing off of the Great Lakes and will feel like doing nothing else.) So long as they are not in a breeding situation, that fast should not be a problem.

In a sense, the nitrogen cycle is being imported with the water. By fasting the fish, the water is hopefully not dirtied too badly. Essentially those bowls, usually on a warm, often somewhat shaded shelf, are for observation and, in one case, medication. If dosage is pro-rated for a small container (1/20 of a ten-gallon dosage) without a lot of gravel or plants, application is easier and cheaper.

Have committed to a killifish show this weekend in Elkhart, Indiana. From the standpoint of fellowship, passing out flyers for the Chicago April 9-10 show, keeping up as a judge (which sounds more impressive than it is) and staying in touch, it is important to attend. That doesn't do the fish here much good. It will be nearly impossible to buy anything new because there simply isn't much room to quarantine anybody new.

Oh ... well there is that one vacated, clean ten-gallon tank, full of seasoned water with the biologically active gravel. ;)

Also used one of your tricks for one bowl Miskairal. It is on the glass top of my only heated tank. It is holding at 75 degrees F, a tad cool for lineatus, but at least it is not fluctuating.

If there was something "suspicious" in either a drum bowl or a large-mouthed gallon pickle jar (which seem unlimited in supply), after the fish were in them, they are emptied down the toilet or laundry sink and parked upside down for the winter in an out of the way corner of the patio. Hopefully the cold will kill any "germs". The bleach bucket, in the spring, will finish the cleaning job. By then, there can be quite a fleet, out there in "dry dock".