So, last few weeks I've been catching my GSP pacing off and on. Up and down the glass. Up and down. First I just moved her decorations around (they are extensive, she's about 2.5" in a 20G standard). This pissed her off as usual but seemed to have no other effect. She was back to the pacing in a couple of days, after pouting and refusing to eat because I dared to change anything in her tank. Waited a few days, added some more decorations (just cheap fake plants, mostly as filler to break up line of sight) and this didn't seem to make a difference either. Tried putting things in as caves for her to look in, all of that. Don't know what else to try. I've attempted adding tank mates in the past, but she is never happy about this and makes a concerted effort to murder them every time. They've all been returned within 24 hours for their own good, every time. Ideas? I can't really get a bigger tank now (space and budget), but with the amount going on in her current one I doubt more space or potential points of interest is really the fix here... Water quality is excellent, 0/0/20 or less. I do a 50% change every 2 weeks or so. She's the only thing in there apart from some ghost shrimp, so bio-load is fairly low. I have a Penguin 350B filter on the tank.