Weak/Variable Connection between our Macs and our WiFi router I have a Belkin N+ Wireless router. Up until recently, it was reliably connecting my husband's Mac Pro (wired), my Mac Mini, our iPad, and a couple of video game consoles (all wireless) to the Internet. The problem started when we bought a network storage drive (wired), mainly to back up my husband's computer. After we got it set up with Time Machine, the router started requiring daily hard resets. After checking around online, I tried updating the router's firmware and eventually got it to accept the latest version. The need to reset to router has decreased since then, but we're still need to do it from time to time. The bigger issue is that our connection speed on the iPad is ridiculously inconsistent. I've been getting anywhere from around 25Mpbs - where it should be - to well under 512k. 

NEW UPDATE: I've been experimenting with position of the router and it's antennae with limited success. Connections speeds on the iPad remain high in the basement, low on the second floor, and super variable one the first floor. (I realize that the basement is not an ideal place for the router, but I don't have a better option and it worked previously.) I've been on the first floor doing nothing and had SpeedTest record speeds around 25Mbps, around 13Mbps, and under 1Mbps in the space of half an hour.

So now the question is, why is my router performing so poorly when it was fine just a few weeks ago? How can I get it back to providing reasonable speeds for my entire house?
When you added the NAS to the LAN did you move the router?  It's possible that even a very minor shift in the position of the router or the antenna could impact the shape of the signal zone.

You might try pairing up with your husband where one of you is in by the router and the other in key use-areas and recording signal strength based on the location, orientation and position of the router and router antennas. (don't know if this model has external antenna, if not rotating the router itself).

There are tools that can give you more detailed report on the signal strength, for instance you might want to download and install Kismac on your MacBook.  Kismac and similar tools can also give you some insight into what other networks might be interfering with your own.  If you see strong signals on the same channel that you are using you might consider moving your network to another channel.