# Carboy question

**URL:** <https://forum.homebrewersassociation.org/t/carboy-question/4845>\
**Category:** General Homebrew Discussion\
**Created:** [February 2, 2011, 4:08pm UTC](https://forum.homebrewersassociation.org/t/carboy-question/4845 "2011-02-02T16:08:07Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![lex82](https://avatars.discourse-cdn.com/v4/letter/l/bb73d2/32.png) [@lex82](https://forum.homebrewersassociation.org/u/lex82)\
**Post date:** [February 2, 2011, 4:08pm UTC](https://forum.homebrewersassociation.org/t/carboy-question/4845/1 "2011-02-02T16:08:07Z")

</div>

I had to get a carboy for a 2nd fermentor and my LHBS only had 6 gal, and I brew 5 gal batches. Is the head space going to be an issue with future batches?

Thanks for any info

---

<div class="post-metadata">

**Author:** ![timmcmanus](https://sea1.discourse-cdn.com/brewersassociation/user_avatar/forum.homebrewersassociation.org/timmcmanus/32/6091_2.png) [@timmcmanus](https://forum.homebrewersassociation.org/u/timmcmanus)\
**Post date:** [February 2, 2011, 4:18pm UTC](https://forum.homebrewersassociation.org/t/carboy-question/4845/2 "2011-02-02T16:18:36Z")

</div>

No, head space is good.&nbsp; You can use it as your primary and not worry as much about blowoff.

---

<div class="post-metadata">

**Author:** ![lex82](https://avatars.discourse-cdn.com/v4/letter/l/bb73d2/32.png) [@lex82](https://forum.homebrewersassociation.org/u/lex82)\
**Post date:** [February 2, 2011, 4:31pm UTC](https://forum.homebrewersassociation.org/t/carboy-question/4845/3 "2011-02-02T16:31:56Z")

</div>

> [@](#):
>
> No, head space is good.&nbsp; You can use it as your primary and not worry as much about blowoff.

cool, thanks.

---

<div class="post-metadata">

**Author:** ![sespach](https://sea1.discourse-cdn.com/brewersassociation/user_avatar/forum.homebrewersassociation.org/sespach/32/8444_2.png) [@sespach](https://forum.homebrewersassociation.org/u/sespach)\
**Post date:** [February 3, 2011, 4:23pm UTC](https://forum.homebrewersassociation.org/t/carboy-question/4845/4 "2011-02-03T16:23:21Z")

</div>

Go to a toy store and buy a few bags of marbles (unless you still have your collection from childhood) that’ll fit through the neck of the carboy, sanitize them as you would any equipment and slide them into the fermenter to increase the volume inside, decreasing the head space.&nbsp; Glass marbles are easy to clean and sanitize.&nbsp; Be careful not to drop them into the fermenter so they don’t crack themselves or the carboy.

You could also boost the size of your batches to 6 gallons.