Planted Tank Guru
Join Date: Jan 2010
Location: Contra Costa CA
Maximum nitrifying bacteria is in the filter.
Here is how I would do this:
The week before: Clean the filter. Deep vacuum the substrate. This might take a couple of water changes. Accumulate the equipment suggested by the following.
The day of or the day before: Set up new water as if you are doing a larger than 100% water change. If you are using a new substrate that needs to be rinsed do that.
The day of:
1) Turn off and unplug all equipment.
2) Siphon a couple of gallons of water into each of several 5 gallon buckets and move the fish. Schooling fish together. Loaches separate. Carnivorous fish separate. Plants can go in these buckets if there are shrimp or something that likes to cling. Cover the buckets. Fish jump. Fish are less stressed in the dark. Keep the buckets at the right temperature. When the room is cold I wrap them in a thick towel.
3) Remove equipment and keep it safe. Keep the filter media damp and in a high oxygen place. One way to do this is to use a storage bin for the fish and hang the filter over the edge and turn it on. This benefits the fish and the bacteria. Another way is to remove the media from the filter and drop it in a bucket with some water. It does not have to be under water, just damp. Remove rocks, driftwood and ceramic merpeople. This is a good opportunity to treat for algae, if any. These things can soak a while in any of several materials then a good rinse.
4) Finish draining the tank, and use this opportunity to clean the sides and the substrate for when you want to set it up again. Remove the substrate.
5) Swap tanks, making sure the new tank is plumb, level and square. Make sure there is enough room behind it for whatever equipment will be there. (I often do not leave enough room for HOB filters, so end up draining and moving it out an inch or so).
6) Install new substrate, rocks and driftwood. Make hills and valleys. If the substrate is not already wet then add barely enough water to show in the low places, but make sure the substrate is wet through.
7) Plant, misting the plants.
8) Put a plate or plastic bag over the substrate and fill slowly, allowing the water to seep slowly over the sides of the plastic bag. This will minimize clouding.
8b) If the water is way to cloudy, then stop filling and do a water change. Make sure to remove the cloudy water from deep under the substrate.
9) Set up the equipment, plug it in, turn it on when the water is high enough. Make sure it all works. If you have a new filter add the old, cycled media to it, plus enough new media to fill the filter.
10) If there is any doubt about the nitrifying bacteria boost the population with any product that contains Nitrospira species of bacteria.
11) Net the fish out of their buckets. Do not use the water the fish were in. Fish under stress can produce stress hormones and excess ammonia.
the rest of the day: Lights out. Only feed the fish if they are acting normal.
Next day: Lights on, regular cycle. Feed as normal unless there is ammonia. Test for ammonia, nitrite and nitrate. Do a water change if ammonia or nitrite are too high (ammonia over .25 ppm, nitrite over 1 ppm) and dose more Nitrospira.
the rest of the week: Continue to monitor the tank. Feed less if there are ammonia or nitrite showing. Allow the nitrifying bacteria a few days to get going again.