For a low tech tank your fish should provide adequate nutrients for the plants, and any other trace elements will be found in your tap water, if you find that some of the plants are deficient however you could switch to an all in one, if the tank is under 30 Gallons in volume I'd use TPN+ any bigger and I'd want to use dry salts, they're so much cheaper and you can dose your tank daily for fractions of a pence.
I've never kept Torpedo Barbs but personally I wouldn't buy them, this species is vulnerable in the wild due to over fishing and as far as I'm aware it is only Chester zoo that has successfully bred them in captivity, though I have heard reports of fish farms breeding them. Always ask where they were sourced from and try and get captive bred specimens if you can.