starting a 20g

Hey Nemo,
I know most of the companys that sell the LS recommend 1 pound per gallon, and for the LR I would say the more the better. I dont know what you plan to use for filtration but the more LR the better bio filtration you would have.
The general rule is 1 to 1.5 pound per gallon but I would fill the tank up to the top IMO
Good luck!
-Jordan

 

I'd not worry so much about the skimmer right off the bat. Nothing to skim really and not any real need for the added 0'2 at that point either. But I'd think about a penguin bio wheel filter a little extra water and they do both biological and mechanical filtration and the wheels keep the bacteria really oxygenated. I never rally used one myself until I inherited a F/W full of African cichlids and they do a great job I never had water to run so clear with a really overloaded tank and to small of a filter for that 75 . I know they would rock on a small salt tank. I had all the fish from that crowded 75 in a 20 H then a 20 L and the filter did a great job still until I could unload most of the fish. But the 20 is crystal clear still and always has been. Its a Penguin 504 I think ? And you can not hear a sound from it. And also as for sand ? Just use a good aragonite and seed it with a cup from your 55 no need to waste money on L/Sand it like rocks will come alive as needed. All the bacteria people add just dies off.

 

i didnt run a skimmer on the 12 for about 3 years. moded ac50 refugium.

but you grow wiser with time and i got a skimmer, and now i have no problem.