Aw, rookie, I'm sorry to hear about your fish. The loss, I believe, is probably directly related to the medication. Loaches and other scaleless fish are extremely sensitive to medications. I believe the only really safe way to treat ich is with heat or a combination of heat and salt. I personally only used salt when my goldfish had it, but that is because he is a cold water fish. The salt WILL work without heat, and I can say that with experience, but it will take a little longer because the life cycle of the ich will be slower. I've had success with doing one tablespoon of aquarium or sea salt (NO iodized table salt) per five gallons of water. Salt will also be easy on your plants, whereas many ich medications aren't good for them.
Rea, I have read about turning off the lights in the tank and putting a towel over it to cause a blackout, but the only evidence of this working was that "it would make it harder for the ich to find the fish in the dark" so I do not think it is worth it, especially if you have plants.
Also, Rookie, you can certainly repair your ten. Go to your local fish store and ask if they have tubes of silicone aquarium sealant. It is the rubbery clear sealant that you find on the joints of tanks. It is super easy to use. I would suggest getting hard, stiff plexiglass and cutting it into about the shape of the crack in your tank, but obviously make it bigger than the crack itself, by about two or three inches, to be safe. Then, remember how in elementary school, when told to glue two pieces of paper together, we would draw all kinds of squiggles and designs on the back in glue, instead of just putting a line of glue around the edges? That is what you want to do on one side of the plexiglass. That, or just make rings of silicone on the plexiglass, that way if water gets through one ring of silicone, it might not get through all the others and cause a leak. Then put the plexiglass, silicone side down, over the crack and put something slightly heavy on top to smush it all down. Give it about 24 hours to dry and then put some water in the tank to test for leaks. A leak might not leak right away, so let it sit for a few hours. If there is no leak, I would empty the water and give it another day or so to cure completely, just to be safe. This is exactly how I repaired my tank when it was cracked. Good luck!
