The Skimming beast is dead....Long live beast ver 2

[les]

Excellent Mike, that makes perfect sense now. But what about the air? How much is enough? Is there a hard and fast ratio? And if I made a 50 gallon chamber and just utilized the tubes for getting rid of the foam would the height of the tubes matter?

Les is just 25 gallon skimmer compacity divided by 2000 gallons an hour = .0125 gph to fill the skimmer then I just divided by minutes and then seconds to get how many second it would take to fill the skimmer, in your case it was 45.
You want to have between 15 and 20 percent of the total water volume as air, so you turn off the air input do a measure and then crank the air back on it should only raise the water level between 15 and 20 percent.
Also on figuring out you calculations I based it on having the whole 6 inch tube as part of the mixing chamber.

Remember the mixing chamber is where all the reactions happen and is far more important then the chamber that only the foam travels in.


Mike

 

[zulreef]

Thanks

Les, My skimmer is working very good. Thanks a lot for building it.

Thanks,
Zul

 

[zulreef]

zulreef,

How did you baffel the water inside the skimmer for the risers?

You need to ask Les Peterson that question. He built it.

Zul

 

[Rico]

One thing I have not seen mentioned in this latest go on the thread is the number of tank turnovers desired. When you read the information posted on the ETS site, they recomend a minimum of 1 to optimally 4 tank volume turnover (processed through skimmer) per hour. At the slow rates discussed here 350 gph, that is only 1 turnover on large systems and barely enough. Here is the link to the ETS skimmer mathmatics

http://www.superskimmer.com/skimmer_math.htm

Rick

 

[Maxx]

Rick, I used to refer to that link regularly. The thing to keep in mind is that the information there is provided by ETSS and isgeared towards those types of skimmers.

The majority of the skimmers out on the market are geared towards removing stuff by frequent processing of the water, (hence the higher turnover rates) as opposed to the lomger dwell times of the airstone/counter current models like this. The CC skimmers will actually remove organic that other skimmers wont because of the longer dwell/contact times. So essentially, the CC skimmers (If designed right) are more efficient than other skimmers.

Nick

 

[les]

Rick,
The next skimmer I have on the drawing boards will run about 800 GPH with the 180+ second dwell time. As we discussed on the phone last night that makes for a mixing chamber of at least 45 gallons. (with baffles) I'll start cutting acrylic this weekend on Sunday if you want to take a look.

 

[les]

You're most welcome, I am glad you like it. I'm sure you have or will notice a large improvment over you old little one.

Les, My skimmer is working very good. Thanks a lot for building it.

Thanks,
Zul

 

[mojoreef]

Hiay Rick
I went to the link, thier concept of skimmer efficiency is just ridiculas.Efficiency should be measured by how much and of what you remove from the tank, not how much water is processed and the amount of pump power required to do it. if your not processing all you want to process then it really doesnt matter how big the pump is or how many times it goes through the skimmer.
You can go turnover rate you have to apply the purity coeffecient. Its not like "I have a 500gph pump and my tank is 500 gallons so I turn over the tank once and hour" . We are looking for a purity coefficient of 9.2 which means that 99.9% of the water has been treated. You are not going to treat all the water in your tank in any one given pass. You will treat a portion of the 500gph with each pass as you are going to treat some of the same water you just treated or treated a few minutes ago, that make sence?? The formula for figuring that out is Gallons of tank water devided by the feed pump and then times by the coefficiency rate of 9.2 (which is 99.9% of the water treated). So in the above example if the person had a 500 gallon tank and the feed pump is a 500 gph pump then its 500/500 = 1 X 9.2 which means that the skimmer will see 99.99% of the water in your tank every 9.2 hours. Make sence?? I have trouble trying to explain this stuff sometimes.

Les

But what about the air? How much is enough? Is there a hard and fast ratio?

Yea their is, you want between 15 and 20% of the total volume to be air. If you have more then this you will cause the bubbles to become unstable and blend and eventually pop.

And if I made a 50 gallon chamber and just utilized the tubes for getting rid of the foam would the height of the tubes matter?

No not really Les you want to make the height of the tubes effective for getting the end product out with out making the skimate to wet (as in you are removing more water then foam. So whatever works that way, all the reactions and skimming takes place in the mixing chamber.

Nick the concept of protien skimming has laws that govern it, those laws apply to all skimmer types with out exception. SOme skimmers follow those principles, some dont at all and then everything inbetween. You can measure what ever skimmer you have efficiency by appling the math to them.


Mike

 

[Reefdaddy1]

So in the above example if the person had a 500 gallon tank and the feed pump is a 500 gph pump then its 500/500 = 1 X 9.2 which means that the skimmer will see 99.99% of the water in your tank every 9.2 hours. Make sence?? I have trouble trying to explain this stuff sometimes.

So your saying that if I have a 180 then a 180 gph pump would suffice for sustained contact time?

Yea their is, you want between 15 and 20% of the total volume to be air. If you have more then this you will cause the bubbles to become unstable and blend and eventually pop..

Assuming Iam running a 5 gal contact chamber, How many stones (6 inch)
would you require?

No not really Les you want to make the height of the tubes effective for getting the end product out with out making the skimate to wet (as in you are removing more water then foam. So whatever works that way, all the reactions and skimming takes place in the mixing chamber.

would a 6 inch tube be large enough to prevent blending of bubbles? and approx how High should the tube be. (ballpark figure that is) Also would a gate valve suffice in adjusting water levels in thsi config? Here are the concerns for me, being I never built anything simular to this config. But it seems that it is more effecient and cost savings over the long haul. I dont wish to overpower it with ie.. 4 stones at 6 inch each when I can get the results with 2.

 

[mojoreef]

Reefdaddy take a peek at this thread first. Its complicated to explain the whole thing and I did it here already. I think it will answer all your questions, if not come on back.

http://www.reeffrontiers.com/forums/showthread.php?t=8250


mike

 

[Rico]

Mojo,

The reason I referenced the ETS link was to ensure the factor of tank water turnover was included in the design discussion. I can see you have with the purity coefficient. Right now I am not convinced about the formula you provide. The reason is that when I was sizing my UV sterilzer, I often referenced the "Aquatic Systems Engineering" book.
http://www.amazon.com/gp/product/1888381108/103-7882378-1305466?v=glance&n=283155
From my recollection (I don't have the book readily available) the formula for tank turnover and near 100% exposure to UV (or skimming in this case) resulted in a greater flow rate than your example. I belive you have the book and there is a great chart that will give the proper flow rate for a given system to get the desired exposure. I'm sorry I can't verify the numbers as I have loaned out my book.

Thanks for the great input

Rick

 

[mojoreef]

Yea I checked it


MIke