I've picked up some juvies appx 10 months old and their size is appx 1 inch.

They have been fed once per evening when the lights go out with a very small variety consisting of Hikari carnivore pellets and Sera shrimp pellets.
I wish to change their diet as I believe that it has been too restrictive and not enough variety.
What do you all reccommend for best growth rates? At their current size I am very wary of giving the wrong foods to them (I want to discontinue the shrimp pellets as I have had bloated/constipated dead 333 fry before from these).
Do any of you feed spirulina wafers etc? I'm considering getting 100% pure pharmaceutical grade from my local chemist as a supplement to the carnivorous diet that is the main staple diet. Also has anyone fed them Tetra colour granules and are these ok for some variation?
Thanks in advance for any advice you can offer, Zeblover.