how are you merging them? im curious, because i have 3, 5 gals i would like to make either a 10 or 15 gal tank.
Usually you just get a new tank, pull some decor or filter media (the more you can pull the better) from one that is already set up to jump start the new tank. Still have to add some
ammonia (
fish food or whatever your poison) to keep the bacteria alive. Just want to move things over as quickly as possible. If you use substrate from one tank, you're even further along. But plants, decor, filter media, substrate all has
beneficial bacteria on it and will be good to get that new tank running. I usually do this and add snails right away to get the ammonia. I have also added a couple smaller fish or a single fish, like a
pleco to a new tank when done in this manner.
You will still want to test it, especially if you start off with adding a fish or two. Also, with 3 5g tanks, you can probably pick the one you want to transfer the most or all of the stuff from to the new tank, hold the fish, break down the 5g, setup the 15-20g, then add the fish you pulled from that 5g. as long as you keep everything wet and can do it in around 2 hours, you're good. If you can keep a
sponge filter or soemthing running in a bucket, you can do it longer. the 2 hours part is to keep the bacteria alive. Then just add the other fish from other tanks slowly over the course of a few weeks. keep testing though.
