Here's how I do a WC on my 8g biocube. First, do a water change when it's needed. Which on this size of a tank should be twice a week! Like I'm supposed to be doing, but haven't been. I was doing it once a week. Why twice a week you ask? Because tonight when I did my regular Friday night WC (no I don't have a life) I couldn't believe my eyes. The filter was soooooo freaking dirty, omg! This thing was black! From just 7 days.
So what I did was first used a turkey baster and blew everything off gently. While trying to get into every little crack and crevice. Then allowed the filter to clear some of it out. Then I unplugged the filter pump, blew again and started siphoning. While this was going on I took out the old filter pads ( I tried the pillow stuffing before and really didn't like it) I buy the kind now that comes in the big squares and cut to fit. This stuff works great! This time I did something new, I added a small carbon filled sock to chamber #1. Don't ask me why, just seems like a good idea to me. May or may not help, but cant hurt as long as I remember to rinse it off with every WC. So, while the waters at it's lowest I do all the do that needs to be done. I got a hermit, he likes to move stuff around and the Nassarius snails do too. Specially the coral frag plugs with the thingy on the bottom. Who ever makes them should put some kind of pedestal on the bottom to keep them from falling over, know what I mean?
Anyways, after having already mixed my water the night before, allowing it to mix with a power head. I test that water for, sg/ph/cal/kh. Being consistent here is the #1 key. No shocky to the live stocky, see? I then put the water into 1g very clean Lipton Tea jugs via a funnel. Bring the jugs, which have caps on em, no spilly, no mess. I plug the filter back in and begin to add my new water directly into chamber #3, where the pump is, slowly while watching my max level line at the same time. Not so easy the first couple of times and that level window is a pain to see in. But I got me a trusty lil flashlight I use for this and peeking at the tank at night. Using these jugs was 1 of the best ideas I've come up with (actually I think it's the only one) very easy clean pour. Wha La I'm done! After about 20min of not so hard work, I can sit back, relax and enjoy watching my zoo's jumping for joy now that they can breath again. The fish are no longer wearing goggles to protect their eyes from debris. My house is clean!!
I hope you enjoyed this read as much as I've enjoyed writing it. It's the first time I've actually put down into words exactly how I do a WC. Maybe it might help someone else with a wee bitty tank.