What do you have in your filter that you changed? The filter manufacturer's will recommend that you change the filter pad/cartridge every 4 weeks but that is usually totally unecessary. You were just doing what the directions said though, so don't fault yourself! If you only have a small amount of media (materials that grow good bacteria for your tank) in your filter and ytou change them, you are getting rid of all that good bacteria every time and restarting the cycling process.
What kind of media does your filter have in it? Usual things are sponges, filter pads, sometimes they will come with ceramic cylinders/noodles, there are other types too. To grow a really good colony of good bacteria you need lots of good media and that must never be thrown out, changed or washed with tap water. Chlorine in tap water kills good bacteria. Most filters, especially ones that come with tank set ups, do not have enough media for a good bacteria colony to grow, so you might want to pick up some ceramic cylinders/noodles to shove in there. If there is carbon/charcoal in your filter you will not need it, it is really only good for removing medications and takes up valuable space for good bacteria to grow-better to use that space for ceramic cylinders or otehr media. When your filter pad gets all mucky, simply pull it out and swish it around in a bowl of used tank water (or dechlorinated tap water). Once the pad starts actually falling apart, then you can change it out for a new one. This will save you a lot of money too! Anything else in the filter that needs rinsing should always be done with old tank water or dechlorinated tap water.
Another thing that will help while you are cycling, and save you money in the long run, is to
buy some Prime water conditioner. It is pricier than some of the others but will take the place of StressZyme/Stress Coat and do much more for your fish. It is also very concentrated so you will use less and over time it will save you money. Prime will remove chlorine and make the water safe for your fish when changing water, and it also detoxifies ammonia and nitrites while cycling. It is AWESOME for cycling a tank. If you can't afford it now, you can keep using Stress Coat and Stress Zyme, but the Prime will help your fish more and only requires a small amount as opposed to several teaspoons each time.
OK, I always talk too much-keep testing your water and try and
get your ammonia and nitrites as close to 0 as possible, once nitrates start to show up that is a good sign that your cycle is taking hold and things will get MUCH easier.
Here are some great links to read since you are new to this and seem like you are willing to do what it takes to have healthy fish. Congrats on your new fish and doing such a good job!
Here are some important things to read on caring for goldfish:
10 steps to a healthy goldfish:
http://www.kokosgoldfish.com/tensteps.htmlAll about goldfish:
http://www.kokosgoldfish.invisionzone.com/...showtopic=11275Cycling the tank:
http://www.kokosgoldfish.com/cycle.htmlAlso,
on the ich, salt is usually the best thing to treat it with-but if your water conditions are poor it will be very hard to get rid of. You have to use salt with no additives, where the only ingredient listed is SALT. Kosher, ice cream, pickling, sometimes rock salts will usually work, just read the label. Aquarium salts are fine too but are more expensive. You want to add one teaspoon per gallon every 12 hours until you have done this three times, so the total salt is .03% in your tank. So for a 30 gallon you would add 30 teaspoons, wait 12 hour and add 30 more, then wait another 12 and add 30 more. Pull some tank water out with a bowl and mix the salt in it, don't pour directly in the tank or into the filters. It may take a lot of water to dissolve the salt. You will need to replace the salt everytime you do a water change, so once you have it at .03% if you take out 50% of the water, you will need to add back in 45 teaspoons to keep it at the same level. It helps to write down the salt amounts to keep track, because oversalting can be harmful as well. Warm temps help speed the life cycle of ich too, so if you have the cash, a heater can help, just be sure to raise the tempgradually and I think 80 F degrees is the max, but I would wait for confirmation on that. The last thing that will help is to vaccuum the gravel/tank bottom a lot to get the ich out of there. You want5 to vaccuum the gravel at least weekly anyway, the more the better with ich. If you can afford to buy a Python-type siphon this will help you immenselty with water changes and gravel vaccuming. NOTE:
With Ammo-lock you may need to remove it completely before adding the salt-check the package. Some ammonia products release ammonia back into the tank when salt is added which could really harm your fish.