9 month old child with running nose which gets blocked in night. Do you have a family history of allergies and is the child playful ,feeding properly,active then it's mostly viral. Using nasoclear nasal drops every 2 hrly in the nose and giving steam or 0.9% saline nebulization will help. Do not use same saline nasal drops for more than 7 days as after  7 the day the solution in bottle becomes acidic and worsens nasal block.so use a new bottle. Nasivion should be used only at night time and never beyond day 5. Now if child is not improving then use atrax drops .The dose has to be selected by your pediatrics.

There is a popular saying if you treat a cold it goes in 7 days, if you don't treat it will go in 1 week. You can put saline drops to clear the blocked nose. For small running nose there isn't much to do. If baby is otherwise well it will become better soon. No antibiotics are required for small infections which are mostly viral.