I heard you should use a second fermenter so do you actually need one? What is the purpose of it? I have a second bucket but I was planning on using that for combining the beer with the priming sugar for bottling.
Most beers do not need a secondary. Typically I only use one if I'm dry-hopping (although generally these days I do that in the keg) or adding fruit.
Secondary fermentation is an outdated concept. Leave your beer in the primary fermentor an extra week or 2 and accomplish the same thing. This is for normal beers. If you are adding fruit, or souring a beer, or making something like a cider or mead that may need to sit a year or 2, obviously you will need a dedicated secondary vessel(not plastic)
I'd say if your beer is going to take 2-4 weeks to be ready for bottling there is no need for a secondary. I even dry hop in primary and have had good results.
The only time I use a secondary fermentation is if I'm either A) Bulk aging a beer for a couple months, or B) Doing a split batch and adding something to only half the beer. I dry hop and add fruit puree to primary and my results have been just fine.
I always use a secondary. I like to get the beer off the yeast as soon as fermentation stops. That way the beer is not sitting on the trub for weeks. I let the beer sit in the secondary to condition and allow for everything to fall out of suspension. That way when I bottle I get a nice clear beer.
