While it's tempting to say yes! -- just dive into one of the other webservers, the reality is that you first really need to work out what is consuming all of your ram, when, and why. Out of curiosity, what does "a bit more traffic" translate to?
Installing munin (if you haven't already) should help nail it down, together with the standard cli tools, e.g. ps, top, htop, and scripts like
http://www.pixelbeat.org/scripts/ps_mem.py.
Essentially, you need to know what is misbehaving (trying to serve too many requests, spending too much time waiting for a response, etc.), else run the risk of just fixing something that wasn't actually the problem.