[ShaunW]

Quote: Originally Posted by reefkprZ I ran an unnofficial/very unscientific expiriment some months ago to see if I could visually notice a difference in my tank from week to week while running my skimmer on one week and off the next. in the corals I did not notice ANy difference that I could pick out. the only visible difference was my front glass seemed to aquire the "film of obscurity" quicker by about half a day to a day towards the end of the skimmerless week. I would guess due to a slow build up of available phosphates to be consumed. I then ran skimmer-less for an entire month (due to a skimmer malfunction that I was to lazy to repair). I did not notice any difference in the appearance of my tank and inhabitants other than the aforementioned "film of obscurity" having to be cleared every day instead of every 3-4 days at the end of the month.

I am not sure how old you tank is, but once a reef tank has cycled with nitrite undetectable, the bacterial population has become established. From there it will obviously fluctuate with different species gaining greater space and venturing into new niches while others will lose out. But in general once the establishment has been made and the conditions within stabilized (temp, light cycle, nutrients, etc) the population will also stabilize. So my point is that I don't think that running skimmerless or not will make very little difference with all things being equal (no changes in nutrients). Now if you were to run skimmerless and provide a C-source or have a nitrate or phosphate spike then the effects would be different.

The interesting question is how long does it take and really how dynamic is the bacterial population over time? My belief is that it doesn't stabilize completely until the tank is really mature, i.e. more than 2 years old and much of the surface area within is established with either coral or bacterial biofilms. This is why "old" tanks are always more healthy.