Hmm... first of all, are you sure with
Lurking Predators? Its a nice card, but i think in a deck with "only" 31 Creatures without some Top Deck manipulation its not worth the mana.
Then, why are you plaing
Iona's Blessing? it may be useful in some voltron decks, but in yours, I dont see a reason to play this card.
Besides that, the biggest Problem with this deck is the mana base. It may work, yes, but the big amount of tap lands makes you playing on snail speed. If you want to improve it, check my Najeela Deck. The Mana Base in there isn't that expensive, but alot faster, because most of the tap lands have a chance to enter untapped. For your commander you don't have to care about colors, and once he has got some counters, he can do a great job with color fixing.
Then I would add some cards that allow you to cast stuff for free:
Maelstrom Nexus,
Maelstrom Wanderer and
Sunbird's Invocation would be a great start. They offer you some free Counters on Ramos.