Assuming you dont have hard to catch fish and heavily planted tank....This is what I will do...Fill the bucket with tank water 3/4( you can get bucket in any $ store)Catch fish and put in the bucket, use net cover(if you have 1) or thin towel to cover the bucket, put it aside so that fish wont freak out when you work around the tank. Fish can stay in bucket for overnight with out problem.
Now transfer all the remaining water to another bucket( this is not needed)..Uproot plants. put it aside, Better if you store all plants in Zip~lock bag and seal it till you are ready to plant it back...Stay fresh this way.
Remove all substrate transfer to new tank, if you are mixing new substrate wash it separately, Better use old substrate in the bottom and use new substrate to cap old substrate ...Slowly refill the tank with preserved water(if this gives you Peace of mind) which is not necessary. Plant all those removed plant back, place DW, decore etc. Put back you filters and run for say 15-20 minutes.....Transfer fish from bucket and voila! you are done.
Have done this many times in my big tanks...1 thing you need to remember is not to Stress fish and use bit warmer water then what you had in your old tank...temperature wise.....say you had 75 degree~new water should be 77-78 degree.
"The future's uncertain, and the end is always near."
Last edited by JoraaÑ; 06-13-2013 at 01:25 PM.