38 gallon cycling.

[aquarium3]

I bought a 38 gallon tank from petco and need some advice on cycling it. I have it all set up and added some filter sponge from an established filter to add some bb but I forgot to dechlorinate the water so I probably killed the bb on the sponge so I took some other media from another established filter a put it in it. How long will it take to be cycled? Is there anything else I should do?

 

[Jessie J.]

You can take out a gallon of water from the cycling tank, and save it (or dump it) and put in a gallon of water form an established aquarium. This will help it to cycle. But don't swap large amounts of water if you want it to stay the same pH.

 

[Colin_T]

It normally takes around 4-5 weeks for a filter to cycle and for sufficient beneficial filter bacteria to be present and be able to convert ammonia into nitrite and then into nitrate. Your tank might take less time because you used established filter media, but you also had it in chlorinated water for a bit and that will mess things up.

Have lots of aeration/ surface turbulence to maximise the oxygen in the water. Filter bacteria are aerobic and love oxygen.

Keep the pH around 7.0 or slightly above. The bacteria don't like acid water and don't do as well in water that has a pH below 6.6.

Keep ammonia levels below 4ppm (3ppm is good) so the cycling process doesn't stall. If the ammonia level goes too high (above 4ppm) the bacteria will stop growing and you should do a huge water change with dechlorinated water and get the level down.

Add a liquid bacterial supplement at a double dose each day for the first week. Try to add it near the filter intake or where the filter is so the bacteria are more likely to be drawn into the filter.