Originally Posted by Fish4Andy
I have no idea what it was, but most of it has gone with the skimming. The water is crystal clear anyway so thats a good sign.
I don't know how to cycle my tank now, I was told to leave it three days and take a water sample back to the shop. I have read the beginners guide on here but I don't know which option to use. I was tempted to add come Cycle as this is the only thing I have.
I don't want to go against any fish keepers smarter or more experienced than myself here, but I have never waited 3 days to put in a fish. I take a brand new or used aquarium, put in the substrate and decorations, fill it with tap water to about the right temp, dump in the right amount of Stress Coat water conditioner/de-chlorinator (any brand will work), plug in the filters, adjust the heater and watch it work for a couple of hours, then introduce the first starter fish as soon as I know the temp is stable. Been doing it this way for almost 4 decades through maybe 25 or 30 tanks and never had a problem.
I think the key is in choosing the right starter fish in the right quantity and not over-feeding them at all during the break-in period. And like I said, Zebra Danios have served me well for this purpose. They are cheap and hardy. If you don't like them they are usually cheap enough that you can just give them back to the store after they have served their purpose, or work out a trade. They are not my favorite either and I have taken them back many times. For a tank your size I would put in one fish a week for 4 or 5 weeks and feed them sparingly once a day while doing 25% water changes every 3 days or so. After that I would ramp up the number of fish added a week to 2 or 3 of whatever I wanted and continue to feed sparingly until about 6 weeks while continuing the water changes. Then I would go to 2 feedings a day and keep adding a few fish a week till I have what I want. Once I have what I want, I would skin back to weekly or bi-weekly partial water changes and go full tilt with the food, but NEVER over-feed. It generally takes me about 8 weeks to fully cycle and stock a tank, usually without killing a single fish.
Always use a de-chlorinator when re-filling with tap water during the partial changes. I use an old plastic milk jug that has been thoroughly rinsed and kept under the tank for this purpose. A strategically placed hole cut in the top of the handle makes it pour smoother. I put in the right amount of de-chlorinator for every gallon (about 3, maybe 4 drops for Stress Coat brand), fill the jug with tap water to about the right temp by feeling it with my fingers, go dump it into the tank, and repeat till it is topped back off.
25 people will tell you 25 different ways to cycle and maintain a tank, but this exact method, though slow, has worked for me for 38 years without ever testing a drop of water- HOWEVER, our local water supply happens to be above average for use in aquariums I am told. I wouldn't be against you testing yours throughout the process if someone tells you it is a good idea. I just wouldn't recommend fretting over little imperfections too much till the tank is cycled. Like I said, there will be plenty of time to achieve perfection
after-wards - slowly and deliberately.
Good luck, and keep us informed.