Okay, so I have three very addorable Fancy Goldfish in a 46 gal bowfront tank. I used to keep african cichlids in that tank but moved them and wanted to try my hand at Goldfish.
I only plan to keep the three, but in the future might try one more. I know that four is the Max. The tank is filterd by an Aquaclear 500 HOB. And also has a small Cascade internal filter which has a spray bar to add a little more aieration.
I kept most of the water/media from the cichlid tank for the new occupants to avoid a recyle...
I put the goldfish in and about three weeks in noticed a few ick grains on one of the fish.
Because I had no ick meds on hand, I increased the temp to about 84 and added salt. I read this is not the best treatment on most forums/ websites. However some say it is less stressful than chemical medications. The ick quickly cleared and I lowerd the temp gradually about two degrees a day, Of course the ick is back and I am adding heat and salt agian. Can I treat with heat and salt two weeks? Is the ick likey to return after a longer treatment.And how do you keep ick aqay in a coldwater tank>?

Treatment:
Salt
Instructions
Increase the temperature to at least 84-86 degrees as much as the fish can tolerate. Add aquarium or table salt (dissolved in water) at a ratio of 1-3 teaspoons of salt per gallon of water in your tank equivalent to 0.1-0.3% depending on the tolerance level of your fish.

For basic procedures, here are the steps.
1. Dose one teaspoon per gallon of salt or equivalent to 0.1%.
2. After 12 hours and assuming the fish has tolerated it very wellso far, repeat step 1.
3. After another 12 hours, repeat step 1 again.

While waiting, it does not hurt to add a powerhead or airstone to increase the oxygen level. Over the first couple days, your fish will appear worse and will eventually recover as the treatment progresses. In most cases, ich will disappear on the sixth day. However, there is still a probability that some cysts have not yet ruptured so it is advisable to keep the treatment up for full ten days.

If you are not able to raise the temperature at all especially if you are dealing with fish that lack tolerance for temperature above 80 degrees Fahrenheit, you may need to extend the treatment although a good general guideline is to continue 7-10 more days of treatment right after the ich had seemingly disappeared.. At 85 degrees Fahrenheit, the life cycle of ich is quicker. The colder the temperature, the slower the life cycle thus the treatment will extend even longer than required.

The reason for the extension of the treatment cycle has to do with the life cycle of the parasite. The speed of the life cycle is the key as meds (and most treatments) are only effective when the parasite is in a "swimming" mode and looking for a host to burrow into start another part of the life cycle.

The salt treatment works by increasing the "slime coat" around the fish. This slime coat inhibits the ability of the parasite to burrow into the flesh of the fish and complete its life cycle. If the parasite can't get into the flesh it dies.

So, it is important to continue the treatment at least five days after the last sighting of a "white spot". This time frame of at least five days is, IMHO, the shortest period of time. Anytime that I have gotten ich in a tank I try to go at least seven days post white spot sighting. Best of luck in the fight!!

I do not believe that salt will cure ich-- at least, not at the dosages recommended. When I was a retailer, we kept salt levels of 2 tsps. per gallon in all aquaria and it did not stop ich from popping up.

Find a malachite green medication and use it. It's fast and safe and doesn't permanently color water.

I successfully used coppersafe. It says you don't have to heat the water, but I left it at 80+ degrees for a month and used coppersafe for a month until I was sure the ick was gone.

www.goldfishstuff.com/ich_disease.html

I used to use Quick Cure and salt when I was big into goldfish. Not many true goldfish keepers in the club so not sure what they tend to use these days. Sometimes goldfish are more sensitive to meds.