I have a 90 (48x18x?) gal I am thinking about getting some RBP for but I may have an opportunity to sell the tank. If I did I am thinking about getting a 120 48x24x? that would fit on my current stand. Would it be better in the long run as I have no plane to upgrade it, or would the 90 do fine for this plan? Also I have no Idea how big or how many RBP each tank would hold. I have been researching but have not found the answers yet , Thanks