Stalled?

My cycle seems to be doing things it shouldn't be and I'm wondering if I should take some sort of corrective action. I started July 21st with some filter floss from a friend's tank, filled her up with tap water dosed with Prime, added enough ammonia to bring it to 5 ppm and everything went normal for a while. I experienced a pH crash on the 1st of this month and corrected that with some crushed coral in my filter which I took back out after my pH hit 8.0. What I'm worried about is my nitrites were going down like they're supposed to, then I went out of town Aug 8-11th (I asked my husband to dose the tank with ammonia every day that I was gone and he claims he did) and when I got back the nitrites had gone back up, and my nitrates went down...no water changes and my nitrates spiked at 17ppm on July 29th but went down after that and have fluctuated since. I do have some lava rock in the tank, and I've heard (although only from one source) that it can hold the anaerobic bacteria that eat nitrate but I can't figure out where it's going or why my nitrite converting bacteria suddenly stopped. I use a new API master test kit, I do shake the nitrate bottle and test as instructed, I've kept the temp at 85F for the cycle process, keep a sponge filter and AC 110 running 24/7...my daily recordings are listed below (Date, pH, Ammonia, Nitrite, Nitrate, additions & subtractions...sorry for the weird format, I keep it in an excel spreadsheet). Any advice?


8/4/2008 8.0 0.0 1.5 5.0 3ppm NH
8/5/2008 7.4 0.0 1.0 10.0 3ppm NH
8/6/2008 7.4 0.0 0.75 7.0 3ppm NH
8/7/2008 7.4 0.0 0.75 7.0 3ppm NH
Gone!
8/11/2008 8.0 0.0 1.0 7.0 3ppm NH -Coral
8/12/2008 7.8 0.0 2.0 7.0 3ppm NH
8/13/2008 7.6 0.0 3.0 5.0 3ppm NH
8/14/2008 7.6 0.0 3.0 5.0 3ppm NH
8/15/2008 7.4 0.0 3.0 5.0 3ppm NH +1 small wisteria plant
8/16/2008 7.4 0.0 3.0 5.0 3ppm NH
8/17/2008 7.4 0.0 3.0 5.0 3ppm NH

The 5 ppm was back at the start of the cycle, I just posted the last couple weeks not thinking the beginning was anything unusual...I get readings of 0ppm Ammonia every morning and dose the tank back up to 3ppm after testing. Here's the beginning of my cycle up to my previous post:

Date/pH/Ammonia/Nitrite/Nitrate/Additions & Subtractions
7/21/2008 8.0 5.0 0.0 0.0 +Filter Floss
7/22/2008 7.8 4.0 0.0 0.0
7/23/2008 7.8 4.0 0.0 0.0
7/24/2008 7.8 3.0 0.1 0.0
7/25/2008 7.8 3.0 0.4 2.5
7/26/2008 7.6 3.0 0.6 6.0
7/27/2008 7.8 2.0 1.0 10.0
7/28/2008 7.8 2.0 1.5 10.0 +1ppm NH +Sponge filter
7/29/2008 7.0 1.0 3.0 17.0 +3ppm NH
7/30/2008 6.6 0.5 5.0 6.0 +3ppm NH
7/31/2008 6.4 0.5 5.0 6.0 +3ppm NH
8/1/2008 6.0 1.5 4.0 7.0 +3ppm NH +Coral
8/2/2008 7.0 0.0 3.0 7.0 +3ppm NH +EcoComplete substrate (added to my sand)
8/3/2008 7.2 0.0 2.0 7.0 +3ppm NH

Bump...I'm still lost

Yea, when my pH dropped, I bought some crushed coral and put it in a media bag in my filter...you can see in the top post it went back up after that and I took the coral out after it hit 8.0...seems to have stabilized at 7.4 at this point. I found out after the fact that establishing the bacteria often causes a pH crash in softer waters because the bacteria's rapid reproduction uses up the bicarbonate in the water. This morning's stats are still 7.4 pH, 0 ammonia, 3 nitrites, 5 nitrates....I guess what's bugging me the most is nitrites were getting so close to 0 right before I left for a weekend and I could see progress...then they shot back up without any apparent cause once I was back home and are stuck. Like my 3ppm ammonia every night gets converted directly to 3 ppm nitrites and my nitrates are just being weird since they've been at 5 for a while, but I never did a water change to reduce them from the one day they spiked at 17. I just don't get it and I really want fish...it's like the end of the tunnel was in sight and then bam, I'm stalled.