You can put the probiotic and the electrolytes in the same waterer. If using electrolytes, you really should offer plain water also. The last time I got chicks (through the mail) the customer service people told me not to use electrolytes for their first water. Reason being that if the chicks are super thirsty, (and they will be) they may take in too much electrolytes and mess up their body chemistry. Best to give them sugar water, and PND, then wait and see how it goes. If you choose to do the probiotics, you can do that immediately, Read the labels, and if you have any questions, contact the manufacturer. Do your homework long before your chicks arrive!!! If you use the SAC lytes plus vitamins, you probably shouldn't add PND on top of that! But, IMO, PND is far superior to SAC products. Any time you put ANYTHING in the water, be sure to change it out every 24 hours. Water with additives grows bacteria.