150% of water change with untreated water is wayyyyyyyyyy too much, not only do you Risk your fish when your local water company ****s up, or something dies near your well. You also risk killing off all your beneficial bacteria then you’ll kill your fish when your tank goes into a new cycle.
I know everyone on here pushes huge water changes but let’s get real here. Unless yOur bucket filling while letting prime sit in your water before you put it in the tank your always introducing unwanted things into your tank. But when you do medium water changes you introduce more tolerable levels of bad stuff( very technical I know)
I personally stick to about 30-50% once a week. But I know people that do 10-20% every other day. But in my opinion, unless your pre-treating water the correct way, (not just pouring a couple drops of prime in the bucket then dumping it 10 seconds later.) then anything over 50% and you run the chance of doing more harm then good.
Also proper stocking has a lot to do with the amount and size of your water changes.
*edit* I also like
S
squint
setup.