Doing the 50% partial water change before treatment is sooo essential. Since an uncycled tank or (my specialty in that case in Immediate Help) a dirty tank (along with temperature drops, over crowding, over feeding, adding unquarantined fish, tossing the pet shop water in their bag into the tank and/or stress caused by a bully) are right up there among the causes of an Ich breakout. If there is enough treated, somewhat seasoned water of the same temperature, I might seek to do a 50% partial water change as often as I could. Since theoretically 50% of the medication is being taken out, do a 50% dosage after putting in the new water. (When I was treating my Endler's tank I was lucky enough to be able to change 50% daily for a week. A lot of fish were still lost but there would have been more otherwise.)

By the way, another really important reason for gravel vacuuming everyday during an Ich outbreak is that that removed a lot of the cysts resting in the gravel, soon to break open into scores of moving organisms seeking to re-infect our fish.

The stressful situation suggests that a good air supply should be helpful. That both helps the fish breathe, resist the parasites and heal and may help the cycling process proceed incrementally faster. Can an air stone be temporarily installed?

You indicated that your sister didn't have a gravel vacuum. Maybe you could get her a gravel vac and test kit as an early birthday present. So much organic material settles in the gravel, that it is my prejudice that one shouldn't gravel a tank if they aren't using a gravel vac to go over half the tank, each partial water change. Yes, one can keep a tank without a gravel vacuum, but it is a lot harder. Sort of like entering a canoe race with a rowboat. ;)

If a test kit for ammonia is used and there is a dangerous level of that stuff, another quick fix in addition to the increased partial water changes, is to feed not at all for a day or two. Then feed sparingly. When medication is over, activated carbon (done in a couple of days if taking out medications) or other ammonia absorbers can be used. It does get used up pretty quickly and should be replaced. That is why I only use absorbers and resins for emergencies.

If a fish dies, of course it needs to get removed quickly so the others don't cannibalize it. Rotting meat also sends ammonia supplies skyrocketing.

Do test the water if possible. And I understand that individuals of the free swimming Ich stage may get into that test equipment. That could be bleached or just left in a jar for a day or so. Supposedly those free-swimmers need a host within about 24 or they will starve to death. You mentioned the freezing weather and I would leave that vial outside with other equipment you are trying to make safer. I have not one, but two gravel vacuums outside, "weathering" at the moment.

Salt can irritate guppies' and other fishes' skin to the point where the skin produces a thicker layer of skin slime (mucus) and supposedly this makes it harder for the Ich organisms to colonize the fish. One level tablespoon per gallon probably wouldn't hurt. That could be added with each gallon on a water change too. That does really, really raise the tank's TDS (Total Dissolved Solids). When the fish return to health, as you know, the partial water changes need to be kept up. Maybe in the first partial water change after treatment, add a level teaspoon per gallon that first time so that the drop in TDS isn't so sudden and stressful.

Salt can also help fish to breath better when there is too much ammonia/nitrite/nitrate in the water because the nitrogen in those substances gets taken in through the gills and that can limit the ability of hemoglobin to carry oxygen. Using salt like that hopefully can help the fish absorb the oxygen more efficiently.

Fish that get lethargic breathe less (or struggle to move the gills more) and may sit on the bottom of an aquarium. Those could be dying of nitrogen poisoning. (Sometimes their gills turn from bright red to a red-brown.) If nothing is done, they will die, sometimes in very little time. :(

I was surprised and dismayed to discover that treatment successful to the point that the Ich visually disappears and all the fish look healthy DOES NOT mean that there are no Ich organisms in that tank. Terry Fairfield has suggested that what has happened is that the Ich population dropped to a non-lethal level and the fish's immune systems are able to combat those skin (epidermis because Ich also can coat gills and suffocate fish) parasites.

I suppose an analogy is that we may have cold or flu germs around us. We are fine until preparations for all that the Christmas season involves tires us out. Then our own immune systems aren't as effective as they were and whammo!

Indeed my best explanation for a bloom in that tank of mine (aside from my neglectful care of those Endler's) was that they had Ich cysts in their skin and, from time to time, in the water. Since I had had those fish for 4-5 years, there must have been some level of continuing infection since none of the original Endler's livebearers would still be alive after all that time. One can reasonably suggest that the Ich organisms were transferred from fish to fish and hung on in their tank at a “sub-lethal level”. I hadn't seen any Ich outbreaks in my aquariums in over 20 years. While that does not mean that those little critters weren't in my other aquariums, it was note worthy that the Ich outbreak, when the fish room's temperature dropped abruptly, only happened in that one aquarium. There were 20 nearby, better cared for tanks which weren’t bothered at all.

Those fish in the afflicted 10-gallon had been kept in Endler's only tanks ever since they first were acquired. Endler's from that strain, which were in other quarters, did not show an outbreak of Ich, maybe since their tanks were a lot cleaner and less likely to leave them stressed.

By the way, Buenos Aires tetras (Hyphessobrycon anisitsi, formerly Hemigrammus anisitsi) are great aquarium fishes. They eat anything, including plants and maybe guppy tails. But if there is only one or three if the albinos are also Buenos Aires tetras  they may not have enough company to keep themselves occupied and at that point may have pestered (stressed) the guppies, Betta (which also should not have been in there) and the smaller tetras. Those larger tetras grow to 2.5 to 4 inches and simply would become too robust for guppies. Sort of like keeping your poodle with coyotes. :(

As for not being able to get into GL, I am very frustrated for you. Quite clearly those server problems are partly the cause of less traffic and participation here.

My new exercise program is pounding away on the "reload current page" button (Firefox) or the "refresh" button (Internet Explorer). ;) Boy will one finger become stronger!

Sometimes switching back and forth on the "back one page" arrow helps. And if all else fails (when I've had the computer on for several hours) I'll turn off that machine. After a short interval it will be turned back on and, off line, I'll run the day's maintenance program.

We may be more cleared headed after a nap. Maybe that works for computers too. ;)

Hope some of your sister's fish make it. I fear that they will die off until there are only 2 or 3 left, the number she probably should have started with.

In addition to Immediate Help, here's a little something more on ammonia.
http://www.practicalfishkeeping.co.uk/pfk/pages/show_article.php?article_id=431