Six Gallon Carboy Enough for Primary Fermentation?

So I'm about to brew my first batch ever and I purchased this equipment kit: http://www.amazon.com/gp/product/B002BU7CVM/?tag=skimlinks_replacement-20

It comes with a six gallon carboy and a 7.8 gallon bottling bucket.

I'd really like to watch the fermentation process for my first five gallon batch so I would prefer to use the glass carboy. Is a six gallon carboy enough for primary fermentation of a five-gallon batch?

I plan on storing it in the guest bathroom which has a window in it. Will it ferment fine as long as the window is covered with shade or do I need to try and fit the fermenting container underneath a counter? Should I try to keep the container elevated (in a stable position) so I don't have to move it when I rack to the bottling bucket or does it not matter if I move the fermentation container around after fermentation is complete?

Fermenting in a carboy is pretty common around here. Most prefer to use a blow off tube instead of an airlock just in case the fermentation gets a little wild. A blow off tube is just a length of tubing that fits tightly in the neck of the carboy with the other end hanging down into a small bucket with sanitizer in it. The bucket acts as an airlock and the tube allows for fermentations that produce A LOT of krausen to expand beyond the carboy without exploding.

That being said, it is possible to just use an airlock in the carboy. Some yeasts won't go that crazy in primary while others are insanely active. My last 3 batches I did primary in the carboy with an airlock and had no problems, so I say go for it. In the end, the worst that will happen is the airlock will become clogged with yeast goo and the pressure inside the carboy will build up to the point where it shoots the airlock and bung out splattering the area with crud.

Yes, a 6 gal carboy should be enough for a 5 gal batch, even with krausen. I use a 6.5 gal carboy for 5.5 gal and there's plenty of room. It's even better if you use a blowoff tube instead of a simple air lock, just in case...

You can always wrap the carboy in a blanket to protect it from sunlight, just watch your temps.

I move my carboy after fermentation all the time to rack into a secondary or keg. Just let it sit for 30 minutes or so to let it settle back again.

Hope this helps.

I think it's a great idea to start by watching the process through glass. I just got a six gallon better bottle and it's a good middle ground between my plastic bucket and my 5 gallon glass carboys. The former is boring because you can't see anything and the latter are too exciting during the first few days with heavy, heavy blowoff.

Above advice about blowoff tubes, carboy moving, and UV protection sounds good to me. Also, if you're fermenting by a window you're more susceptible to temperature fluctuation than, say, a dark basement. A few degrees' flucuation is okay, but try to keep the temp static at your chosen level; those stick on thermometers (fermometers) are nice for measurement.

Have fun on your first brew day!

As you can see, using a 6 gallon carboy for 5 gallon batches is perfectly fine. You can even safely ferment 5-1/4 or 5-1/2 gallon batches. If you don't want to worry about needing a blow-off tube and such, you can get some fermcap, include that in the boil, and not worry about it. ~2-3 drops per gallon is the common amount to put into your boiling wort (do it at the start, and you can fill your pot to within 1/2" of the lip and not make a mess).

I've used it twice now in the boil, and have had zero need for blow-off tubes when fermenting. First time was with 5 gallons of wort into a 5 gallon corny, with just an airlock fitted. Second time was a brew started Thursday evening. I actually brewed with someone that's been using it for many batches. Mostly due to not having a large pot (he has just a 5 gallon port for BIAB) and not wanting to add too much water to top off. I used it the second time so that there wouldn't be any worry with the batch. Besides, it's fermenting at his place right now. Even once I'm fermenting where I live (hopefully I'll be in a place where that won't be an issue soon enough) I'll continue to use it... For the couple of dollars the stuff costs, it pays for itself in just a few batches. Especially when you consider not needing to worry about finding foam all over the walls, or on the floor, and possibly having an airlock embedded in the ceiling.

I'll tell you what I do. When I started I bought a 6 gal carboy and still use it, but I prefer my 6.5s. I wait for a good cold break and don't add the trub to the carboy. I also use a 1.25" blow off tube. I usually come close to a 5gal batch doing it this way.