Benefits of an Oversized Skimmer

[tommer725]

I was thinking. What would happen if I were to put a skimmer for say 150 or more gallons on a 20-30 gallon tank. What would happen? Would it give me more slack on water changes and all? The proteins would be practically non-existent in this tank, but could it also strip out the good in the water? I am just putting this up for discussion.

 

[Reefvet]

Would it give me more slack on water changes and all? ..., but could it also strip out the good in the water? I am just putting this up for discussion.

Yes and yes.

But water changes are about a lot more than just removing the DOCs a skimmer takes out and over-skimming it pretty hard to do in reality.


It's very common to run a skimmer that's rated for many times your tanks capacity. The key is to look at the effects on your reef and it's inhabitants and learn what's needed. There's a place for nutrient rich, under-skimmer tanks.

 

[scubadan206]

I think it would just spin its wheels so to speak. It would pull out all it can in short time and then do nothing for a while. Some tanks need big powerfull skimmers to control unwanted nutrients. I would prefer a little [under-skimming] and let the bio-filtration do more of the work.
Most people just use a sump as a place to keep this stuff out of the way. I would rather use it [the sump], refugium style, and let it be some of my filtration, rather than just a place to keep the filtration hidden. Many people have understandably limited space for this stuff. I am lucky in that I have a place for it, but my sump will be 1/3 larger than my display, and use lots of live-rock in addition to the usual, skimmer, filter socks, and reactors exc.
Daniel:wildone:

 

[ca1ore]

I run an ASM G3 skimmer rated at 250 gallons on a 30 gallon reef and it seems to have no adverse effects. Skimmers only pull out about 30% of the DOC so this whole notion of over stripping the water is a red herring IMO.

 

[Kairus]

If it's too big it might not be as effective. There may not be enough DOCs in the water to build enough foam up in the skimmer to push it all out, so it could be hard to adjust, and may not be able to pull everything out a smaller sized body skimmer could.

 

[tommer725]

I was watching a podcast today and heard about skimming too. I also heard that a skimmer isn't very efficient and pulls about 30 to 60 percent of the proteins. I think that it would be something that could be done. We are all still learning though about this hobby.

 

[Atomic081]

Putting a skimmer rated too big for your tank usually doest work cause you need enough doc to go over the top. Its also hard to dial in a oversized skimmer cause you raise the water level so high to compensate for the low doc and any influx of bioload will overflow the skimmer.

 

[gardy]

im running a reef octopus BH1000 on a 16g Bowfront............it has taken a while to tune in, and its skimming really wet (emptying the cup every other day) but the water is crystal clear. if i were to do it again i wouldnt have used one so big on such a small tank, but it did gain me a gallon of volume.

 

[Reefvet]

I think it would just spin its wheels so to speak. It would pull out all it can in short time and then do nothing for a while.

That's going to be true of any skimmer even if there are DOCs in the water that can be removed. Enough of the water has to actually pass through the skimmer, the skimmer has to be producing enough foam to fraction-ate the DOCS from the water and if there's anything in the water that's reducing the surface tension it won't be able to work with what it's had passed through it.

Here's a good article on the fundamentals of how a skimmer works.

We are all still learning though about this hobby.

Undoubtedly that's true for all of us.

While skimmers have ratings for tanks sizes they're a bit like EPA mileage ratings, you may never achieve what's promised.

And over-skimming is a red hearing as someone posted earlier. It can happen, but's it's not very likely.

 

[tommer725]

That's going to be true of any skimmer even if there are DOCs in the water that can be removed. Enough of the water has to actually pass through the skimmer, the skimmer has to be producing enough foam to fraction-ate the DOCS from the water and if there's anything in the water that's reducing the surface tension it won't be able to work with what it's had passed through it.

Here's a good article on the fundamentals of how a skimmer works.



Undoubtedly that's true for all of us.

While skimmers have ratings for tanks sizes they're a bit like EPA mileage ratings, you may never achieve what's promised.

And over-skimming is a red hearing as someone posted earlier. It can happen, but's it's not very likely.

How big would one have to go to achieve "over-skimming?"

 

[Timber77]

its gonna depend on the skimmer style. a bigger beckett or very tall counter current venturi is gonna work fine on a smaller tank. a short fat needle wheel skimmer with a wide neck might not have enough foam build up on the wide neck to get it into the cup very well. I run a 3 pump 12 inch H&S rate for 500-1000 gallons on a 180 gallon over stocked tank and it works great.

 

[tommer725]

I run a 3 pump 12 inch H&S rate for 500-1000 gallons on a 180 gallon over stocked tank and it works great.

Yes. Stocking would be an issue to discuss as well.

 

[gardy]

Yes. Stocking would be an issue to discuss as well.

I think the only reason I'm able to tune this bh1000 was the tank finally reaching a heavily stocked state

 

[andycook]

The trouble is that many skimmer size ratings are over stated so when you try to put an allegedly "oversized" skimmer you aren't doing what you think you are doing.