how much crushed coral do i put in 20 gallon tank...?

Question

I have a 20 gallon tank setup for brackish water but i am not sure how much crushed coral is hould put in with my gravel. I have a 10 pound bag i got from the fish store but after the 20 pounds of gravel or what ever am i supposed to put all that crushed coral in to? or is there a set amount i should use?

so i should take some of the gravel out and just add all the crushed coral and kinda mix it in and around the gravel?

Answer 1

There isn't really a set amount. If you're using the crushed coral as a pH / KH buffer, then you'll just have to monitor your pH and KH levels and adjust them accordingly (don't forget that you can also use baking soda to buffer it). You can also set up a power filter with only crushed coral in it (no filter filter media) if you don't want to mix the CC into your substrate.
Otherwise, I'd do about 15-20 lbs of each gravel and CC, give or take, so you have about a 2-3" gravel/CC bed. But if you go with 20 lbs gravel / 10 lbs crushed coral, I'm sure that will suffice.
Or you can use exclusively crushed coral. You can't use too much, really, unless you're filling the tank halfway full with it :)

Answer 2

Just use the coral, not coral and gravel. Add it about like you would gravel though... maybe about 3-5 lbs per gallon of the tank, depending on shape and how deep you want it to be.

MM