You need either a substrate for the nitrogen cycle to take effect or larg water changes. How much water to change, and how much media in you filter, will depend on bio load.
Because you have no established filter, you will likely be doing large water changes for a month. Monitor the cycle, change water as needed. Using some rock rubble out of your tank in the filter will greatly speed up this process, don't reuse it if your using chemicals.
NOTE! When you throw sponges away, you throw away lots of good bacteria. Don't do it till your done your hospital treatment.
|