What someone else is dripping should not reflect what you should drip, everyone has diffrent things. What you should be putting into consideration is, YOUR total gallons, how much bio load YOUR tank as, and how much gallons YOU want to change a week.
For instance, if you have 1000g system, and in a week span, you wanna do a 50% WC, thats 500gl WC a week, so that roughly 71gl per day, have it run like that for a couple weeks and do a water param check, if its not handling YOUR bio load, up the GPD. If your doing fine, try dropping the GPD (for the sake of a smaller water bill) and see if params are ok. If they are, then good, if not, obviously up the gpd again. You have to find a balance between cost and the health of your fish. Once youve acheived that your good, until you add more fish lol.
I know your asking how much gallons in ones system, and how much theyre dripping, but my point is if you find someone who has the same gallons as you, does not mean you should drip the same amount, they might have more or less bio load than you, which is why you need to just start it and adjust it so suit your needs.
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