For 5 gallons.
When you rack from the primary add 1/4 teaspoon of sulfite to your wine along with any fining agent such as bentonite or sparkolloid to name two. Blend well. Later on when you rack again you are exposing your wine to air again and you need to maintain proper levels of sulfite in your wine. I add a pinch to the carboy, then rack the wine into it. This will blend it.
From here since your wine is cleared and should be degassed, you can add oak if you like or just let it age for 6-12 months.
The small amount of sediment that may still drop out is fine.
Next time you rack to back sweeten or get it off of the oak you will add another pinch of sulfite again.
Somewhere along the line get a titration kit (@ $20.00) and take a test to show yourself how much each period has in sulfite.
Now you mentioned it's in it's secondary fermentation period now. I would not add any until it is all finished fermenting. I ferment all of my wines dry in the primary. Transferring to an enclosed container too soon can cause a miriad of problems.