Skimming conversation
- Thread starter mojoreef
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mojoreef I think Deltec has been longer in market than any US brand I can think of.
IMO & IME what ever it's made in USA must be big - big means good.
I disagree with that kind of judgement.Becked -Downdraft skimmers use pressure rated pumps to make bubbles.Recirculating skimmers don't need large feeding pump.I don't think the size of neck can have impact on skimming performance. IMO biger skimmer biger neck biger pump.If you wont put big-tall neck on these monster you are going run the water thru the skimmer
IMO & IME what ever it's made in USA must be big - big means good.
I disagree with that kind of judgement.Becked -Downdraft skimmers use pressure rated pumps to make bubbles.Recirculating skimmers don't need large feeding pump.I don't think the size of neck can have impact on skimming performance. IMO biger skimmer biger neck biger pump.If you wont put big-tall neck on these monster you are going run the water thru the skimmer
Tsadik I wasnt really refering to european or US made skimmers, just the newer skimmers in general. From the early days it was said that the larger neck made for a more concentrated protien skimmate? thus the question. So what purpose would a neck make on a skimmer??, some european skimmers still use them and so do some us made ones.
MIke
MIke
ldrhawke
John
mojoreef said:
I believe the size of the neck and the amount of air being pumped through the skimmer are directly related. A skimmer that has a low air volume would need a smaller neck to get the desired final few inches of lift pumping the skimmate into the cup. If you are pumping a lot of air you can use a larger neck and still get lift moving the skimmate up into the cup. :idea:
I ran some test tonight to compare the air pumping action between the Sedra 900 pinwheel pump and the 3/4" Mazzei Venturi Injector using a std, Sedra 900 pump to feed it, before I installed them on my Mod skimmer, even though I plan on using both. After I throttled down the air, they both foamed pretty good. It looked like the Sedra 900 pinwheel produced about 50% more air. I'm guessing by the amount of air I will be running much lower levels below the neck in the skimmer to keep from pumping too wet a skimmate.
The Sedra 900 feed pump will be feeding about 4 gpm through the skimmer throttled back by the venturi. This will be about 4 to 5 tank turn overs per hour. Still awaiting a few fitting to finish the project.
Wouldnt a skimmer that has a low air volume be a lousy Skimmer?? Just trying to bring back some of the old timer stuff I keep forgeting. From what I remember its all about the more bubbles you can make (regardless of type) then not to have to much violence to break the bubbles, then a decent neck to concentrate the skimate. Thats the way it was way back has it changed and I missed the boat?? again
Mike
ldrhawke
John
mojoreef said:Wouldnt a skimmer that has a low air volume be a lousy Skimmer?? Just trying to bring back some of the old timer stuff I keep forgeting. From what I remember its all about the more bubbles you can make (regardless of type) then not to have to much violence to break the bubbles, then a decent neck to concentrate the skimate. Thats the way it was way back has it changed and I missed the boat?? again
Low air volume be a lousy skimmer.....Only if you had too much organic waste for the amount of air supplied to handle. It's all relative, which is why they make so many different size skimmers
I always wonder how a skimmer mfg decide a cetain model skimmer can handle a 50 to 125 gal system with out knowing the tank biolgical load and your feeding habits.One size and one air volume doesn't handle all tank sizes. Unless of course it can if it is over sized to start. I agree more bubbles are always better. Of course it cost more to buy and operate an over sized skimmer. A $3,000 skimmer would look funny on a Nano tank. I'd bet you'd have a clean tank and happy coral and fish though.
Scooterman
Well-known member
Humm, I wonder about that, you'd think a longer neck would act like a channel for the skimmate. Smaller skimmers, pumps = less output so I guess the neck size would proportionally be smaller also. Air to surface area would to me seem to be the equation, for a give cubic volume of a water column, you could only add so many air bubbles before saturation of that water. I would think at some point too much air bubbles would not help or even become a waste, also you could use compression, or smaller bubbles to a point of micro bubbles & cram in more air to water ratio but even so at some point I'd say you will reach saturation. So ok, we figure out the saturation point of micro bubbles per given area of water. So if we can produce saturation for any given skimmer, you would reach peak performance for that size skimmer right? So a taller, wider skimmer that you reach saturation would handle twice as much (or proportion to size) as a smaller skimmer half the size or is this not so? I guess this is how the manufactures figure their skimmer will perform. So with that said, all we need to do is figure out how to maximize micro bubbles for a given amount of water in a given column, then learn how to increase sizes proportionally, then you would reach peak performance for that size skimmer, so if you want more, all you could do is go to a bigger skimmer.
ldrhawke
John
Scooterman said:
In municipal and industrial waste treatment plants, they often take it a step further using compressed air and a tank pressure concept. In dissolve air floation thickening systems, which is a batch concept, you put the liguid waste in a pressure tank and pumping in fine bubbles under high pressure, after a period of time the waste becomes saturated with dissolved air. They then release the tank pressure and the waste into an open tank. The air within the solid particles expand and float the particles to the surface. The surface of the water becomes covered with a blanket of solids which is skimmed off.
In a tall skimmer, to a minor degree the same thing is happening. The air expands in and around the waste particles as it rises to the top of the skimmer carrying the waste with it to the top. One of the reasons tall commerical skimmers are designed compared short skimmers of the same volume. Tall skimmers remove more waste. Of course you pay a price in operation cost. It takes more energy to pressurize the air and force it to the bottom of a tall skimmer. The same way it requires energy to pressurize a venturi to make it work or inject water under pressure to cause foam to build in a Becket or a down draft. No free lunch.
I believe it is as important to consider in any reef tank skimmer; besides efficiency, the ease of set up, stability once it is set up, and required maintenance of a skimmer to keep in operating well. These are some of the reasons the Euro Reef pinwheel pump skimmer design has been so successful. It is almost plug in and walk away design. It has addressed these points and gained a following. It isn't that other designs cannot be made to work or that they are less efficient, but they are often much more sensative in selecting right high pressure feed pump and keeping orifices from partially clogging. To keep small more efficient bubble making orifces from partially plugging, you can go to large orifces and higher pressure and flow to cause foaming action, but you pay for it in energy consumed in a higher head and flow rated pump required to do that.
Just my thoughts on the topic...
Of course I could be wrong.....I use to think Liz Taylor was going to become a nun too.
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Scotty good post I am with you.
Let me ask you guys one question did anybody here know if european reefers are using any of american made skimmers?
I know of only a few Tsadik, the richer ones, lol. The Aquarium equipment is driven by different forces in europe then it is in the US. In europe thier is a huge concern about energy cost, so the equipment R&D is driven by that. Thus the low energy PH skimmers using needle wheels. It the states it tends still to be a concern but not as much as it is in Europe.
Good conversation folks!!!!!!!!!!
Mike
Let me ask you guys one question did anybody here know if european reefers are using any of american made skimmers?
I know of only a few Tsadik, the richer ones, lol. The Aquarium equipment is driven by different forces in europe then it is in the US. In europe thier is a huge concern about energy cost, so the equipment R&D is driven by that. Thus the low energy PH skimmers using needle wheels. It the states it tends still to be a concern but not as much as it is in Europe.
Good conversation folks!!!!!!!!!!
Mike
I think it is bubble surface area, not bubble volume that you want. That is why those airstone skimmers (with their tiny bubbles) were actually quite effective.mojoreef said:Wouldnt a skimmer that has a low air volume be a lousy Skimmer?? Just trying to bring back some of the old timer stuff I keep forgeting. From what I remember its all about the more bubbles you can make (regardless of type) then not to have to much violence to break the bubbles, then a decent neck to concentrate the skimate. Thats the way it was way back has it changed and I missed the boat?? again
Mike
From my limited observations, the becket skimmers tend to produce larger bubbles. But they make up for that shortcoming by creating huge volumes of those larger bubbles, so they still have more surface area (and often greater organic removal).
ldrhawke
John
dnjan said:
You're right fine bubbles are generally better because you get more surface area, but if you do not have enough air volume you don't get enough pumping action into the cup. i have noticed that with higher air volume I get from running an ejector along with the pinwheel pump, the higher air volume seems to pick up and put larger particles of waste into the cup quicker.
I try to pull at least a pint a day of skimmate and at times I do run my skimmate pretty wet doing this. Sometimes the skimmate is only the color of tea, and other times it can get very dark brown. It varies up and down based on the tank organic loading from feeding or additives.
When I add my daily 1 ml/ 100L dose of Vodka, using my modified cheap Zeo system, a few hours later the skimmer takes off removing bacteria loaded with N and P.....but that is another topic :lol:
ldrhawke
John
Tsadik said:
I think you will find pinwheel pumps gives the best bang for the energy buck, compared to ejectors and nozzle design skimmer that require a higher pressure pump. You have to measure actual current draw and cannot go by the pumps name plate wattage on a pinwheel pump using an ejector pulling air into it. On a Seda 900, if I remember it says 70 watts. The actual pumping capacity and specific gravity of the pumpage drop way off because of the entrained air, so the load drops off. A centrifugal pump motor amperage is directly related to the load it sees. It is like pumping whipped cream. You probably pull less than 1/2 the pump name plate wattage using it as a pinwheel pump..
Zephrant
Engineer
Scooterman said:Humm, I wonder about that, you'd think a longer neck would act like a channel for the skimmate./QUOTE]
Consider it this way- What ever skimmate enters the bottom of the neck, you want to exit the top, to be collected in the cup (the whole purpose of the skimmer of course). Anything that inhibits that foam from exiting the neck is bad.
Take it to extremes- Which works better, a skimmer with a 6" neck or one with a 24" neck? All else being equal, the extra 18" of neck just gives you that much more acrylic to clean. It also gives the foam that much more time to break down, and drip back in to the main chamber.
"Get the foam out!" should be the mantra of all skimmer designs.
Zeph
Zephrant
Engineer
I think Mike has a good point here:
Some manufactures claim that their designs are "plankton friendly", which is a bunch of crap. All venturi run the water though a small area of high pressure- Anything traveling along with the water gets a burp of higher pressure as they go though it. Not always fatal, but not friendly.
The "spinning pins of death" of pin wheels and needle wheels cannot be considered friendly.
Spraying water though a nozzle (high pressure, no pressure in the air, crashing in to the water surface) is not friendly.
Hosing water down a tube of bio-balls ("static balls of death") is not friendly.
The only design that can really claim that is an air-lift / air-stone design. And even then those poor planktons are being harassed continuously by bubbles.
Zeph
mojoreef said:
Some manufactures claim that their designs are "plankton friendly", which is a bunch of crap. All venturi run the water though a small area of high pressure- Anything traveling along with the water gets a burp of higher pressure as they go though it. Not always fatal, but not friendly.
The "spinning pins of death" of pin wheels and needle wheels cannot be considered friendly.
Spraying water though a nozzle (high pressure, no pressure in the air, crashing in to the water surface) is not friendly.
Hosing water down a tube of bio-balls ("static balls of death") is not friendly.
The only design that can really claim that is an air-lift / air-stone design. And even then those poor planktons are being harassed continuously by bubbles.
Zeph
ldrhawke
John
mojoreef said:Compare that to an airstone and pump?? cheaper up front, cheaper to run and more air bubbles with no violence
MIke
I have compared an airpump to a pinwheel pump. To get the same amount of air that a pinwheel pumps put into the skimmer you need a good size air pump that takes even more energy than the pinwheel to run. Using compressed air in any type of process is never cheap. Plus they are often noisier and require more maintenance than a magdrive pump. Let alone air stone replacement. If you can make bubbles without using a compressor, it is the way to go.
