Hi guys,

Recently converted my 2ft tropical to cold water for goldfish. I removed the gravel, cleaned the filter media using the old water, retain and reuse about 1/4 of the old water retrieved straight off filter, top it back up to full and let it run for a few days, checked the parameters, good PH, no ammonia, no nitrites, no nitrates. Weird, maybe I've accidentally killed off all my bacteria or maybe there's nothing for them to process.

Anyway, bought 2 ryukin bout 2 inches on friday, test the water today, ammonia gone up to 1ppm, nitrite 0ppm, nitrate 5ppm. I've fed them only once a day, water remains clear, they both looked fine, and active. So, I reckon the filter shld be working and cycled as one is from the previous setup and the other sponge filter I took from my other tropical tank. What I dun get is why is there ammonia?? Is it due to lack of flow?

I understand goldfish gives out plenty of waste, but with 2 proper cycled filter, it should cope with it. Btw, in the process of building a wet/dry trickle filter using a 1ft tank that's in storage. If I add that to this, hopefully, will increase the ratio per fish and increase water flow.

Please advise. Have attached couple of pics as well.

IPB Image

IPB Image