My Halfmoon Betta Fish Habitat : My First 5 Gallon Tank Setup

Описание: First, Sorry for the missing focus!! I still noob at this...hard to get the focus right XP

This is my setup for my new 5 Gallon tank,
Inside I got my Beautiful Male Halfmoon Beta : Hikki is his Name, He's really look comfortable in his house^^ even I put my hands inside, he doesn't afraid or run from me.. :)
I got him Tankmates : 3 Oto Catfish/Otocinclus
They seems get along well, well, the oto still afraid of Hikki tho.. but yeah they seems enjoy their own home :)

I plan to put 3 more Corydoras inside the Tank, what do you all think? is it too many fishes in 5 Gallon tank? comment me ur suggestion, thank you!

Fish :
1 Royal Blue Halfmoon Betta
3 Otocinclus/Oto catfish

Plant :
7 Big Marimos/Moss Balls
11 Small Marimos/Moss Balls

Ornament:
1 Ceramic Vase Cave
2 Plastic Aquaplant
2 Wide Leaf Silk Plants
5 'Eceng Gondok' Silk PLants
White Snow Gravels
A few of Arcylic Crystal and Balls
Sushi Mat as Aquarium Background (I put it outside back of the tank, so it won't rot!)

Tank : Nisso NS Medium 18 Litre
Filter : Resun CY-20
Lamp : LED 2 watt Lamp and 12 Watt Lamp

UPDATE 2014
The Green Balls/Marimo all still alive and healthy..
but my Pretty Hikki is died because of the water condition :(
All the Ottos are healthy alive :)