internal or external skimmer

[royvoss]

lookiing for the proc and cons to each. i have room to do both. looking for opionions.

thanks.

[Rouselb]

Internal you will not have to worry about water pumping in and out of your sump. I run mine external, and i would run internal, but cant fit it.

[dadonoflaw]

well an external gives you the option of running it in and out of the sump in case needs change. also external skimmers are less prone to loose head when feeding.

[royvoss]

ttt

[szeth13]

"less prone to lose head when feeding"??? hu? i dont think im as down with the lingo as i thought i was

[USC-fan]

Are we talking about external recir nw vs insump nw skimmers?

[pjf]

The main advantage of most external skimmers is that you can feed it directly from the overflow (gravity feeding) instead of buying a sump pump to feed it. This saves energy and allows surface water with the greatest protein concentration to enter the skimmer.

[royvoss]

the external one i am looking at is a recir. gravity will be on my side. sump will be located in the basemment. incase anybody is wondering. it is a h&s skimmer. they offer the same model in both. most of the skimmers i have seen are in the sump.

[Rouselb]

I have a MRC recirc, its a beckett skimmer. When i fed it from my overflow there was not enough throughput. I had to run a small powerhead to get the skimmer to function properly.

[sjm817]

Originally posted by pjf
The main advantage of most external skimmers is that you can feed it directly from the overflow (gravity feeding) instead of buying a sump pump to feed it. This saves energy and allows surface water with the greatest protein concentration to enter the skimmer.

Internal skimmers generally dont need a pump to feed them. In the example of an internal NW skimmer, the NW pump is the feed pump. An external NW skimmer has a NW recirc pump and also needs to be fed via gravity from the drain, or a feed pump.

All water that enters a skimmer or a sump comes from the overflow. Same amount of proteins come down the drain regardless of the skimmer type used. With an in sump skimmer, you have to pay more attention to sump layout and design than with an external.

[pjf]

“So... why don’t you get such daily skimmate? There are many common reasons for this. The number one reason is the quality of water delivered to the skimmer. Anything less than raw water overflowed straight into the skimmer is a compromise.�

-Anthony Calfo (http://reefcentral.com/forums/showth...5&pagenumber=1)

[sjm817]

From that same page...

If you put an Aqua C Remora on a tank with a Seaclone... you will be converted my friend

That Aqua C model is categorically the best HOB skimmer IMO at any price and also happens to be a good value. FWIW

-Anthony Calfo (http://reefcentral.com/forums/showth...5&pagenumber=1)

Remora, the best HOB? Cant say I agree with that one.

Since we are doing quotes, here is another one:

We presently run both internal and external of the same model and they preform very very close to same. I do not see a big difference between either one.

-Fins Reef U.S. H&S distributor (http://www.reefcentral.com/forums/sh...readid=1137432)

[CruzinKim]

You have the best control over your skimmer on a recirculating skimmer. If you are referring to needlewheel type skimmers, you can install a external in sump or out.

[pjf]

Proteins float. They should be skimmed from the surface of the water, not from the bottom of a sump. Anything else is a compromise.

[Rouselb]

i agree its best to feed the skimmer from the surface. I have a MRC dual beckett skimmer (recir) and i feed it from the bottom of my fuge..I have a cup of skimmate every day or two.

[sjm817]

So the proteins instantly separate from the water column and race to the surface as soon as the water hits the sump? Interesting theory. Strange that in sump skimmers seem to pull them out anyway and actually do it better in a less turbulent sump which is completely counter to that idea.

No comment on what H&S says about their actual experience of their internals and externals?

I'm not going to argue this since it will go on forever. What caught my eye on this thread was the odd idea that a disadvantage of an internal is the need for a feed pump which is of course, exactly the opposite of the the truth.

[royvoss]

is it good idea to feed the external with gravity? my plan is to send about 25% of the drain to the refum and the rest to the skimmer section. split with two valves. one to he skimmer and the other to the skimmer section of the sump. i should be able to tune fine with the valves. putting this on a tech 120. the drain are rate 600 gph each. will be using 1.5 or 2 inch pipe. depends what will fit . the sump is going to be in the basement. not sure how gravity will affect the drain. an other opinions are welcome. i am still open to ideas. thanks for the replies. i also checked the a h&h dealer , the skimmer need about 400 gph flowing to it.

roy

[sjm817]

I'm not wild about direct drain to fuge. You will get a lot of detritus accumulation. I run a basement sump and fuge. One thing to consider is the water will be really cruising coming down the drains and will be carrying a lot of air with it. This will make the skimmer feed design important. You need to feed the skimmer water, not big air bubbles from the drain. The method for doing this has been posted a few times, but I dont have a link to it handy.

[royvoss]

fyi, the model of dkimmer is a h&s a200-1260 rated up to 300 gal tank. mine is a 120 the sump is going to be around 75 to 100 gal.

[USC-fan]

recirculating skimmer perform better and is just a better skimmer design. There is NO question about.....

[CruzinKim]

Originally posted by royvoss
fyi, the model of dkimmer is a h&s a200-1260 rated up to 300 gal tank. mine is a 120 the sump is going to be around 75 to 100 gal.

I'm not sure what others think, but in my opinion, A200 is too big and you don't need it. A150 is a better match to what you plan on doing. I have seen a couple owners with 120g tanks that felt their A200 skimmer was a bit much for their setup.

[royvoss]

not looking to start a debate, if the skimmer is a bit over sized what will happen. many people i a have talk to in the lfs , use the larger filter and skimmers when possible. all I am trying to do is save myself some aggravation and expense buying something that is to small or not up to the job. i am still on the fence over the internal / external setup. i guess if gravity feeding does not work i could feed it with another pump form the skimmer section of the sump.

[royvoss]

if some one on rc has an external skimmer, i would be interested with your input.

[Rouselb]

I can tell you that a recirculating skimmer really produces alot of skimmate, but it also takes alot of power to drive it. I have the MRC dual beckett recirc skimmer. I first tried to feed it from a overflow, i even submerged the overflow so it was sucking water from under the surface ( i know, skim from the surface), but i was trying to reduce the bubbles in the skimmer. There were too many bubbles in the skimmer from the overflow. It still was not really skimming right, so i threw a mag 7 in to feed the skimmer and it bean to really skim. My fuge is in the basement, and my skimmer is running externally. If you dont have a large load on your system, i would think a NW skimmer would be a better alternative (internal or external), the power consumption would be much less. Just my opinion.

[CruzinKim]

Originally posted by royvoss
not looking to start a debate, if the skimmer is a bit over sized what will happen. many people i a have talk to in the lfs , use the larger filter and skimmers when possible. all I am trying to do is save myself some aggravation and expense buying something that is to small or not up to the job. i am still on the fence over the internal / external setup. i guess if gravity feeding does not work i could feed it with another pump form the skimmer section of the sump.

Several have referred to oversizing as "severely oversized skimmer syndrome" in the reasearch I've been doing. Below is just one quote that I came across, there are many others. But one must really know the particular skimmer line very well... as many of the manufacturer's rated capacities are grossly exaggerated. I agree, a little oversize is fine, save some room for growth for the future, but severely oversized is not a good thing. For 120g setup, IMHO, A150 is a better fit than the A200.

http://www.reefcentral.com/forums/sh...7#post10716867

Originally posted by Freds
Ed is on smack to recommend a BM 200 for a 90 gallon tank. I think it was on zeo but it may have been a European forum, Oliver stated that people should NOT be buying oversized BMs for their tanks. I ran a BM 200 on a Bare bottom heavy stocked, heavy fed 90 and it was WAY too big a skimmer. It pulled out tar for the first two weeks and then nothing (symptom of too big a skimmer syndrome). It would pull out nasty skimmate after I fed but then go back to idle until more food was given.

To deal with the collapsing foam, or overflowing issues, have your controller kill the skimmer for 20 minutes after you feed. After 20-30 minutes the oils from the food will have dispersed enough to allow your skimmer to function normally again.