Originally Posted by etanico
I'm about to get a new 5 gallon tank. I've never done the whole "partial" water changes thing. I've always just done full with the 1 gallon, unfiltered tanks that I've had. When I'm only doing the 25-50% water change in this new tank, do I still take the fish out? If not, is it really safe for me to put the water conditioner right in the water, if the fish is still inside?
If youre doing the 25%, then no. Take care to not suck the fish up if you have a siphon, though. Add back water that already has conditioner in it and that is the same temp as the tank's water.
50% changes are trickier, and I suggest you take him out unless he has at least 4inches of water to swim in. Taking him out will be the safest bet, though. To reacclimate when taken out:
Take out of the tank with its cup, with the old water in the cup.
Change the water, add back the new water with conditioner.
Bob the fish in the cup for 5 minutes, addint a tsp-tbsp of new tank water in every 5 minutes. Do this for at least 15 minutes.