Biorb life 30l marine conversion help

Hi. I have a biorb live 30l. Using the marine filter and heater , and have

About 3kg live rock cycling for 4 weeks now, I'm gonna do some changes.

1- cancel the biorb marine filter.

2- add a internal filter or external .

3- add sand

4- add a power head.

Do I need Any thing else ?



A external filter gonna give me more Room for livestock ?

Or small internal filter gonna do same job ?

What to put inside of the filter etc.

What filter to buy ? Internal or external ? Make etc . Need a silent and small .

Need some advice on filter please,



Then advice in livestock ?

Fish + coral and cleaner crew

Thank you in advance