Hi, everyone , am new to this but basically am after some advice, have been keeping tropical fish for about a year now and have just ordered a rio 400 to upgrade. I want to continue with tropical but want to have my new tank in marine design as my current tank looks crap. i was thinking of jus having ocean rock inside but unsure what colour gravel would be best and would also like tank to look blue but dont think juwel do blue lights? any help and advice please ,,, much appreciated thanks