I would start with 3 or 4 ml of calmag and completely mix it into a gallon of water, then I would add 3 to 5 ml of grow big and completely mix it in the same gallon of water, then I would mix in 3 to 5 ml of big bloom. That would make your total added around 10 to 15 ml per gallon to start and probably give you a ppm of around 500 which is low but good to start. After the plants use the water you give you can see if they are happy and want more the next time or if they start to get some clawing or spots then you know you need to back off a bit. Eventually you will be giving them more but small plants don't need much.