New tank not cycling

Question
Hi Jamie

I have a 4 week old 20 gallon tank with 3 small (1 inch long not counting the tail) fantail goldfish in it. My problem is that it just won't seem to cycle at all. I have an Aquaclear 30 hang on filter with a carbon insert, I feed the fish 2 fish flakes per fish each morning and night (with peas or freeze dried tubifex instead sometimes) and I have been testing the water every day (with an API Freshwater Master test kit) and it just stays at either 0.25 or 0.5 Ammonia (hard to tell as the colours are pretty similar), 0.0 Nitrite, 0.0 Nitrate and 7.4 pH. And it has stayed like this for 4 weeks now with no change..... For the first 2.5 weeks I was worried about the ammonia level and was changing 15% of the water every 2 days, but someone told me that was too often and that was why the tank wasn't cycling, so after that I switched to doing one 25% water change per week (have only done 2 of these so far) and it hasn't seemed to have made any difference. I thought the ammonia would increase at least, but it hasn't - it's still staying at 0.25. Also - 4 days ago the fish started getting cloudy/opaque white fins and splits in their tails so I have been putting Melafix in (I removed the carbon in the filter first), which seems to be helping the fish a lot, but do you think this is killing the bacteria and stopping the tank from cycling? Should I do anything differently to what I am doing now, or should I just have patience? I am conscious that the fish have been swimming in ammonia water for a month now which can't be good for them, but I heard putting ammonia-lock products in will stop the tank from cycling so I'm not sure whether to do that or not. Also I don't have access to an established tank for some gravel/bacteria to put in, and the only bacteria additive products available here in NZ seem to be 'Cycle' and 'Stress-zyme', which I have heard don't work. So I think I have to do it eau-naturale. Any suggestions?

Answer
It is perfectly normal to only have ammonia readings at this point.  It takes up to 8 weeks to cycle.  I would do a 50% water change everytime the ammonia gets above .25...this will not affect the cycle, but will help your fish.  Just be patient and it will cycle eventually.  Cycle and stress zyme do't work, see if you can get Biospira.  But frequent water changes and patience is what will help.