Because of how it removes good coral food. I wrote an article a few years ago for the Sea Star. Anyone wishing to read it may email me and I'll attach it to the reply.

The exception may be that SPS seem to do better (at least this is still my safest opinion) with very nutrient poor water. I may be revising my position after I see how well the SPS do in my skimmerless heavily stocked 10 gal after about six more months of observation under heavy feeding.

 mrpslc@mstar2.net

Hey Mark,

It's probably me that you should direct your question to. I run a skimmer on my tank. Why would I only want to concern myself with running it when housing SPS?

In my 10 gal tank without skimming but an extremely heavy filter feeding population, it takes approxiamately 2 hours for the cloudiness caused by 2 cups of phytoplankton to disappear. I suggest that each hobbyist do their own observation and let that determine how long to leave the skimmer off.

Don't turn off water circulating pumps. That's how plankton gets to the coral! And actually the more (more not faster) water movement the better.

But Mike, why are you using a skimmer anyway? I know your tank. Your tank is too new and has too little for the coral to eat as it is. You really don't need to even consider using a skimmer for another six months unless you plan to add a lot of SPS coral.

I'm sure it does.  The problem with skimmers (if there is a problem) is that they work too well.  They are incredibly well designed and efficient.  I'm sure they pull out phyto.  I would turn my skimmer down, or off when adding phyto.  I don't know of any good studies or data on this subject, but I have heard people say that when they dump in phyto they can watch their skimmer cup fill up.

Adam

I would like to hear some opinions on this subject. Or even hard data if someone has some.

Thx,
Jason