So i was wondering how often i should change the water in my fish tank. i have a jar and a green phantom in there. It is a 60 gallon tank with a Aqueon 55 filter.
Well ya don't state what size the jardini or the other fish is. What you need to do is test your water for nitrate levels. Change enough water to keep the nitrate levels below 20ppm If not to much of a hassle then shoot for 10ppm.
As a note when I was raising a baby black aro in a 55g(about 40g of water) I could go three weeks before the nitrates got above 10ppm. This was only while it was very small. The best thing is just to get in the habit of changing the water weekly. Eventually once the jar gets big it will require this anyways.