Originally Posted by fishy314
I have just moved my betta from a 1g to a 2.5g and there is conflicting information on how often I should change the water.(SNIP)
What would you do? I don't know who to trust.
What you should do is buy a test kit so you can actually understand what's going on in your tank's water. You should test ammonia, nitrites, and nitrates a couple times a week for at least a few months while you're getting the hang of it. Remember: if there's nothing wrong with the water, it's not urgent to change it. The only way to know whether it needs
a change is to test it.
If ammonia starts to creep up, do a 50% water change (even if it's early), and add some API Quick Start. (You should add some Quick Start now to get the tank cycle started.) Otherwise, if things are testing good, just do a 20% or so water change once a week as a matter of general good practice.
Unless the water gets VERY bad, don't do a 100% change, ever. It could be a shock to the fish. Even if something is very wrong, don't do a 100% change, do a 50% change and follow it a few hours later by another 50% change and test everything again to see if the water is good enough or if it needs another 50% change a few hours later.
I am assuming that your new 2.5g tank is heated and filtered. If not, it should be.