I know I've read a few times over the years that 2 skimmers can somehow limit each other and that a single appropriately rated one will out-perform them. I don't recall the rationale but my instinct is to run one.

Having said that I've run across a few amazing large tank builds over at RC running 2 although if I recall correctly they were both high-end skimmers each already rated to handle the user's load.

I meant as you get up in size for pumps, they are made with better parts than the lower end pumps. That is what I meant by cheaper.

Most extra large systems i've seen use 2 large retail skimmers rather than one custom. Seems like a great system for redundancy, etc. Larger doesn't always mean better, I'd take 2 BK mini's over most 300 gallon skimmers. If you're planning on spending a bunch of money i'd go for 2 smaller ones. But, 250-300 gallon rating isn't a HUGE skimmer, so there's lots of available options that will skim damn near anything you have, unless you're going NPS :P.

IMO one skimmer would be best. Less cost overall, less space taken up and less work to maintain and clean. Dwell time is also important in skimming so a larger skimmer would give you higher dwell time. If you use ozone it becomes even more important.

For example 2 x 4"dia skimmer = 25 sq in of area while 1 x 8" dia skimmer = 50.25 sq in of area.

I could always sell you my used "Big Bertha" skimmer, it is 33" diameter and 8' tall. ;)

Cheers,
Tim

What if both fails when you are on vacation? not likely but it could. I ran 2 skimmers on my 72 gallon and then went to a single over size skimmer. I like it better due to the rate of the oversize skimmer skimed, and the larger volume of water being processed compare to 2 smaller ones. I do believe you tank turn over rate will also play a important roll in your choice of skimmer. I am a strong beliver on at least match or surpass the turn over rate so that the skimmer can handle all the water that has been through your sump. If your turn over is 500 gph but the skimmer only can handle 250 gph even with 2 skimmers it might not have enough contact and dewell time to process all the water. I think I also read some where I think on rc when there is 2 skimmer in the same sump area one might become dominate and strave the 2 skimmer. when I had both of mine running, in some instance it did seem to be some what true. of course there are a lot of variable that need to take into consideration.
ultimately the choice is your Mark, but for me one less piece of equipment, one less plug in, one less skimmer cup I have to clean out works for me. If none of these you are concerned about then I say go for it, but maybe try 2 medium size skimmers that will total more than your turn over rate and let me know how it goes.

Good luck.:wink:

I would also vote for the buying one good skimmer. I am not sure what skimmer you use now, but i switched from an asm g3 to my current bubbleking and i would not want to have to clean 2 of the cups one is bad enough. The best bet is to look around and look at peoples skimmers and get reviews. You don't really see anyone running two skimmers it is cost related or what. I agree with Brett and I think i have read two will act against each other. If your moving into the higher end of skimmers and buying 2 it can get real costly even if there smaller. I have used my bk for 3 years and have never had a non human/ snail caused issue.

I currently have a euro reef cs 63 and was gonna add a euro reef rs180

Or just take out the euroreef and get a vertex in250

Vertex alpha 250... Can't go wrong with red dragon pump. I haven't yet to meet anyone who owned a alpha or bbk that didn't like it.

lol 1200 dollars for a skimmer?

i'd rather take my chances buying a cheaper skimmer even if i have to go through 5 of them in the life of one of those alpha skimmers

My first "saltwater" buy was my skimmer.... will be the backbone of whatever system i run for probably the rest of my life.....Unless i get divorced or win the lotto..... In which case.... Im buying 2 pools one for the fish and one for me to soak and wach them in :)