ha yeah, what I have for you will easily outgrow the 10 and the 5.5 and your other tanks. I have lots of Ludwigia Repens waiting to send you and this stuff grows like a weed, literally. All you have to do is snip and replant. As for the peacock gudgeons, give them a little cave, nothing huge, a sandy substrate, lots of plants and good food. They get along with just about anything their size, I have otos with mine and plan to add some pygmy cories. The males have more of a blunt head than the females, both have beautiful coloring, the female will have black edging on her fins. Don't worry if the male disappears for a long time, he's guarding eggs. For the longest time I thought my male died until I saw him chasing free swimming fry. Oh, and yeah, they will eat the fry. They're also pretty hardy, just make sure the tank is stable first. I have no problems with water changes.