I think flow might be an issue (maybe), however the low flow side of my tank has significantly less slime than the high side. i also have an old MH bulb on the side with more slime / flow which could be a part of my problem. It's just wierd to me that all of the normal inhibitors of slime algae are present on the side that has the slime and are missing from the side without.
BTW it's far to late (and way to many beers) for me to be too detailed. I'll post some things tomorrow that might help. However it's probiably important to point out that this tank is only about 4 months old, has a high bio-load, and has only had tap-water up until about a week ago. Most of the bio-load problem will go away when the 130 gallon is ready to go (don't ask, unless you must), and tap-water will never be used again.