New Skimmer – Price is no Object!

[8BALL_99]

Bean I'm pretty impressed with your skimmer.. Didn't take you for a DIY guy.. If you don't mind me asking. I'm building another CA reactor right now with a 6"x19" Chamber.. What did you use for your print out for your bubble plate.. I made one already but I'm not happy with the looks.. I couldn't figure out how to mark for all the holes and keep them uniform.. I never thought about drawing it out in photoshop or something though..

BTW I did my Flanges the Exact same way.. A router, Tablesaw and drill press is really all you need.

 

[pjf]

It depends on the type of performance that the aquarist is looking for.

• If the aquarist uses ozone or carbon and seeks a large skimmer for fast removal of surface scum only, he may use a test that periodically samples surface scum from the two test tanks. He may be more concerned with the first day’s results and base his decision on that. The large surface skimmer will reach a point of diminishing returns quickly as no new organic material is added to the tanks. I believe that the small skimmer that can skim CDOM will remove surface scum better over time but scientific testing can speak for that.

• If the aquarist wants a skimmer that can skim CDOM, a color card may be used to test the water periodically and the progress charted. The surface skimmer may reach a point of diminishing returns more quickly than the slower CDOM skimmer with its longer contact time. Think of the CDOM skimmer as the tortoise or “Energizer Bunny.”

The advantage of water column testing is that progress can be charted over time. The ozone and carbon user may only need the first day’s results. Other aquarists may want to wait until the “point of diminishing returns” to make a decision on a slower CDOM skimmer.

Skimmate comparisons are difficult. Bacteria may start degrading its contents quickly. Wet skimmate may have to be dried for comparison with dry skimmate. The drying process may result in the loss of VOC’s. Charting quantitative and qualitative analysis over time will be very difficult. Valid skimmate comparisons can be done but it may be easier to test the water quality which is the ultimate goal.

As for Deltec versus H&S testing:

- If half the initial tests show Deltec edges H&S and half the initial tests show H&S edges Deltec, then the two are close in performance. The split between the tests does not invalidate the tests.
- If you don't think testing is necessary, they will not improve their products. They will remain high-priced with the pricing based on anecdotes such as yours.

 

[BeanAnimal]

<a href=showthread.php?s=&postid=10716725#post10716725 target=_blank>Originally posted</a> by 8BALL_99
Bean I'm pretty impressed with your skimmer.. Didn't take you for a DIY guy..

People always say that. I get a kick out of it. Just becuase I don't endorse every DIY idea that comes down the road, does not mean that I do not like or practice DIY!

"Hey man stop bashing people for DIYing and saving money" gets repeated over and over. But if it is NOT saving you money and is NOT getting you a better product, then why bother? Unless of course you could care less and just want to DIY with little regard for the quality or cost of the finished product.

I DIYed my acrylic sump, skimmer, light bar and pulley system, drilled all of my tanks, automation system, dosing system, water change system, etc. Just because I can show that DIYIng a reflector or an RO/DI unit is a waste of time does not mean that I do not like DIY! I build my own audio equipment and electronics projects. I have remodeled and rewired my entire home. You name a DIY project, and I have likely undertaken it, from casting to fermenting to drag racing and landscaping... I diy a LOT.

If you don't mind me asking. I'm building another CA reactor right now with a 6"x19" Chamber.. What did you use for your print out for your bubble plate..

I used a ghostscript program from MarkS (I think). I had to do a LOT of modification to it to get the thing to print the holes on concentric circles and different ratios.

http://www.reeflogic.com/pub/Ghostscript_flange_calc.zip

You will need ghostscript installed. I have a few files there and have not looked at them in a year, so I dunno if they are the working examples or have erros in them. You may want to find the old thread and go from there.

You could also use any cad program to slap the holes around concentric circle in an array paste. I started to go that route, then saw the thread with the postscript file and just used it.

 

[BeanAnimal]

PJF, with all due respect, you keep saying the exact same thing over and over, but refuse to address any of the dissenting opinion.

Your process has been challenged from a logical, as well as practical standpoint and your answers to those challenges are to repeat the process as if we just don't get it.

The advantage of ANY testing is that it can be charted over time.

Now you are talking about a test to measure surface scum? Diminishing returns? Skimmers with higher capacity for surface scum and time? The problem is that we DO NOT HAVE ANY EASY scientific test and what you have put forth as a scientific test does not pass muster at the most basic level. That has been the point all along. Not that testing is impossible, it is just not practical when the variables are considered.

Any person that is not color blind can tell if the skimmer is removing the yellowing compounds. Color card, water in a bucket, whatever. As mentioned, observation of the skimmer cup, water quality and livestock health is a superb indicator of how well YOUR skimmer is performing on YOUR tank.

We have also established the fact (now several times) that actual testing for compounds in the skimmate is not an easy thing to do.

Nobody said that a split between tests invalidates the tests. The tests are not valid for many other reasons.

You are starting to pad these posts with what we already know, and attempt to paint the picture that there is a lack of understanding.

I would welcome a response to the questions asked. I (we?) understand your proposal and your methodology. I (we?) have questioned several aspects of it and have yet to hear responses to those questions.

 

[pjf]

Thread Redirection

Thread Redirection

It looks like others are picking up the ball when it comes to skimmer testing.

<a href=showthread.php?s=&postid=10715759#post10715759 target=_blank>Originally posted</a> by sirrus6
I have been following this thread with some interest, as in fact I have been testing skimmer performance with the aid of some enthusiastic aquarist/students at Penn State University. (see http://www.reefcentral.com/forums/showthread.php?s=&threadid=1035462).

Specifically, we have purchased one member of each class of skimmer:

needlewheel: EuroReef CS80

venturi: Precision Marine ES 100

downdraft: ETSS evolution 500

airstone: Precision Marine AP 624 (we had them custom-make this skimmer for us)

We then measure the kinetics of bovine serum albumin (BSA, a test case protein available for cheap in large quatities; starting at 10 ppm) depletion in a 35 gal saltwater aquarium under standardized conditions (i.e., volume, flow, temp, etc) using a Pierce microprotein assay kit and Beckman DU70 spectrophotometer.

We have adequately tested the CS80, ES100, and ETSS 500, but only about half the runs on the AP624 are completed. I am currently looking for a new student co-worker to complete these studies, and to perhaps expand to other organics as models for DOC components - for example, the Pierce kit, which is really an oxidation measuring assay, will detect glucose (as a model carbohydrate) down to the ~ 1 ppm level.

I hope to have this preliminary study wrapped up this year (if I can hire the student), and to submit the results to ReefKeeping for publication. We definitely do see differences between the different skimmers in terms of the rate at which they remove BSA from saltwater. I would prefer not to discuss the results in this forum at present, because of the inevitable controversy surrounding the decision to use a model system (i.e., BSA) to represent an unknown (aquarium "protein", or more generally "DOC"). That is, I think that acceptance of any data on a controversial topic such as skimmer performance will require a lot of preliminary explanation and context, best developed within a comprehensive article.

Other tests have been proposed for skimmer testing.

<a href=showthread.php?s=&postid=10716386#post10716386 target=_blank>Originally posted</a> by Boomer
The are called "Color" tests. LaMotte makes two of them, CT-PC and CW-HR. The first is a dual range drop pipet and the latter is a octet comparator with a axial reader. They use platinum cobalt color stds. HACH also make one CO-1. These kits are for apparent color created by dissolved substances. There are also other kits that may work, like the one I sent to Randy. The LaMotte Tannin/Lignin, TL kit or their Phenol kit P-52-R. And the HACH Tannin/Lignin, TA-3 and the Phenol kit PL-1. How well these will work in seawater I don't know.

For those who are interested in skimmer testing, I suggest the following reading:
LaMotte, A Laboratory Manual for Marine Science Studies (http://www.lamotte.com/pages/edu/handbook.html)

 

[pjf]

Thread Refocusing

Thread Refocusing

I'd like to refocus this thread back to its original purpose. I believe that these are the remaining questions of relevance:

• What skimmers do you recommend that will reduce chromophoric dissolved organic compounds (CDOM) without ozone or carbon?

• When P. R. Escobal (Aquatics Systems Engineering: Devices and How They Function) observed that 2 minutes of dwell time was necessary for attachment of certain proteins:

o What proteins was he referring to?
o Was the flow co-current or counter-current?

• Which counter-current, recirculating, or low-turbulence skimmers under 30-inches tall do you recommend for reduction of CDOM without ozone or carbon?

Thanks very much!

 

[BeanAnimal]

PJF,

You have a knack for posting bolded catch phrases and snippets of other peoples work. It is quite obvious that you do so in an attempt to change the focus of conversation from what YOU have said to what THEY are saying. In doing so you always avoid direct defense of your own assertions and logic that have come into question. In almost every case, the cited sources are NOT saying what you are saying.

If you read what you quoted:

I would prefer not to discuss the results in this forum at present, because of the inevitable controversy surrounding the decision to use a model system (i.e., BSA) to represent an unknown (aquarium "protein", or more generally "DOC"). That is, I think that acceptance of any data on a controversial topic such as skimmer performance will require a lot of preliminary explanation and context, best developed within a comprehensive article.

That is EXACTLY what many of us have been saying all along.

Also notice that this is a STUDY that is taking a large number of resources and trials. Something else that has been said all along.

Secondly, nobody ever said that tests have not been proposed. Notice the lack of methodology or conclusions that boomer has drawn? What will the test mean? What is a good skimmer?

We have come full circle once again. Nobody said testing CAN NOT be done. Some of us have said that it can not be EASILY done and that the results are open to a LOT of interpretation due to the number of variables and unknowns.

 

[pjf]

Organics Test Kits

Organics Test Kits

The Salifert Organics Test Kit is not being manufactured anymore. I have not been able to obtain this kit from retailers, such as Aqua Cave, Custom Aquatics, Premium Aquatics, and Salty Critters.

The Hach "Total Organic Carbon" tests only work in freshwater due to interference from chlorine in seawater.

For those interested in skimmer testing, check out the test methods suggested in the above post ("Thread Redirection"). The LaMotte "A Laboratory Manual for Marine Science Studies," should provide food for thought.

 

[pjf]

Remaining Questions

Remaining Questions

This thread does not have to be concerned with testing methodology anymore. Here are the remaining questions before us:

<a href=showthread.php?s=&postid=10718547#post10718547 target=_blank>Originally posted</a> by pjf

• What skimmers do you recommend that will reduce chromophoric dissolved organic compounds (CDOM) without ozone or carbon?

• When P. R. Escobal (Aquatics Systems Engineering: Devices and How They Function) observed that 2 minutes of dwell time was necessary for attachment of certain proteins:

o What proteins was he referring to?
o Was the flow co-current or counter-current?

• Which counter-current, recirculating, or low-turbulence skimmers under 30-inches tall do you recommend for reduction of CDOM without ozone or carbon?

Thanks very much!

 

[BeanAnimal]

o What proteins was he referring to?
o Was the flow co-current or counter-current?

I am not sure that it matters. The counter-current model creates more dwell time in the same vertical space. Increasing the height of a co-current skimmer would arguably also increase the dwell time. The question becomes one of turbulance vs dwell time. And I suppose other variables as well. Neck shape? Riser length? Does the height of the skimmer and columner pressure play a role on bubble size? Surface tension? What about the bubble density?

I would say that the CO-CURRENT, COUNTER-CURRENT question is not as important as the turbulance and dwell time questions

 

[pjf]

Great Design!

Great Design!

Hahnmeister,

Your design below has all of the features that I want:

• Water inlet at top for greater contact height
• Air introduction at the bottom for greater contact height
• Counter-current flow for greater dwell time
• Recirculation
• Bubble plate for reduced turbulence

Let me know where you plan to have it custom-built. For my 100-gallon system, I’m planning to reduce it to dimensions similar to that of an H&S A150-F2001:

• 6-inch diameter body
• 26-inch height (must clear 28” cabinet ceiling)
• 4-inch diameter bubble plate

Thanks very much!

<a href=showthread.php?s=&postid=10713810#post10713810 target=_blank>Originally posted</a> by hahnmeister

 

[BeanAnimal]

• 6-inch diameter body
• 26-inch height (must clear 28” cabinet ceiling)
• 4-inch diameter bubble plate

Thanks very much!

Lets assume 8" for the collection cup and around 5" for the bubble plate height. That leaves you roughly 13" of reaction area.

A 6" diameter body is rather narrow for a skimmer that short. You will be very limited in the size of recirc pump and air that the skimmer body will accomodate.

You need to be looking at a much wider body for a skimmer that short. You stated system size is 100 Gallons.

I hardly think that scaling that skimmer down to those dimensions illustrates the "perfect" skimmer as outlined in your first post of this thread... not to mention nowhere near "price is no object"

I would imagine that hahn would agree. SKINNY skimmers need to be tallk. The height is what creates the calm reaction area and dwell time.

 

[JCTewks]

I don't think you are going to get an answer on a skimmer that will remove CDOM's. I don't think there is one out there.

As to Hahnmeister's skimmer design: the height is what will make it an extremely effective skimmer...If you reduce that to 26" totalheight, well, you just built yourself a BM160! IMO you are NOT going to find a skimmer (if one exists) that will skim CDOM's that will be short and pretty. any skimmer that might get the job done will be TALL.

 

[pjf]

You are correct about the height constraint. It is definitely a compromise. I may consider placing the skimmer outside the cabinet but I would like to take the in-cabinet design as far as it will go first.

The flow rate through the skimmer (75 gph) and the diameter of the bubble plate (4") and body (6") is loosely derived from Escobal's sizing charts (http://www.hawkfish.org/snailman/skimmer101.htm) for a 100-gallon system.

Do let me know what those dimensions should be and why. Thanks!

 

[JCTewks]

those cimensions sound spot on for a system your size....all i am saying is that it needs to be taller. If the skimmers that currently exist on the market that meet those specs and only have 16-20" reaction chambers don't remove CDOM's...why would one that you build be any different...just buy a bubblemaster if you want that. I think if you want any chance of removing the elusive "gelbstoff", or at least having a chance at the "2 minute dwell time" you will have to have a much taller skimmer.

you just can't get that kind of "dwell" in a 26" total height skimmer...even with the bubble plate. having the slow flow and a recirc design will get you lots of bubbles in contact with the water and follow the "quickly stripping the surface scum" idea that you described. but it will not allow for one bubble to exist in the skimmer body for more than 20 seconds or so. you need the tall height so that 1 bubble can remain in contact with 1 protein for the longest time possible for that "stubborn" protein to have a chance at actually attaching to the bubble.

edit/ammendum: a tall as you can would be best. If you can find a place to hide a 48"skimmer next to the tank, go with that...if you can do a 6' or 7' or 8', go with that. the goals you are trying to reach can only be helped by a "the taller the better" line of thinking.

 

[BeanAnimal]

The Quote Game

The Quote Game

Escobal recommends at least 4 feet to 5 feet tall for the reaction chamber to optimize contact time...

...Fossa and Nilsen in The Modern Coral Reef Aquarium volume #1, page 259 recommend that the skimmer reaction chamber should not be any shorter than 28 inches to 32 inches "except for very small aquaria"

The short and fat recirc skimmer is an attempt to rememdy this.

According to Escobal, the upper limit of the amount of air able to be inside the skimmer at any one time is 13% of the water volume inside the skimmer. Escobal does take the reader through the calculations on why this is the uppere limit...

Less air, means less skimming per timespan. Again, short and fat are the answer if height is not available.

There are two keys to injecting air into the skimmer for optimum nutrient export:

1. Keep the air bubbles as small as possible
2. Minimize turbulence of the air bubbles in the skimmer reaction chamber

• Skinny recirc skimmers have a LOT of turbulance to deal with.
• The taller the skimmer the smaller the bubbles due to pressure (does it make a difference... who knows

Are two small skimmers in series better than 1 fat skimmer of the same height?

I would suggest using the largest diameter skimmer body that you can fit in your chosen skimmer area.

The next question: Why not purchase an ASM, OCTO or other similar skimmer that is already built and rather inexpensive. You can get the same basic features and not have to buyild anything. You can MOD the recirc pump with mesh if you like.

Most of us DIY skimmers that we can not afford to buy or that are NOT available for a reasonable price in the size that we desire. If I had a stand that I had to stuff a skimmer in, I would just purchase one ASM, Euroreef, BK or something.

You did say that price was not an object. I think that you can get one hell of a nice BK skimmer to fit in your stand that will almost certainly outperform a scaled down version of the hahnmeisters design (which is meant to be tall and calm).

 

[BeanAnimal]

those cimensions sound spot on for a system your size....all i am saying is that it needs to be taller. If the skimmers that currently exist on the market that meet those specs and only have 16-20" reaction chambers don't remove CDOM's...why would one that you build be any different...

Exactly

 

[BeanAnimal]

those cimensions sound spot on for a system your size....all i am saying is that it needs to be taller. If the skimmers that currently exist on the market that meet those specs and only have 16-20" reaction chambers don't remove CDOM's...why would one that you build be any different...

Exactly

 

[pjf]

How does it stack against the BK?

How does it stack against the BK?

Okay.

I believe that per Escobal's guidelines, my skimmer should be the same height (48") as Hahnmeister's design but narrower (4" diameter bubble plate, 6" diameter body) to fit my 100-gallon system.

Should its counter-current flow allow it to outperform the co-current flow of the BK-160 or BK-180?

 

[BeanAnimal]

That would work much better than what you originally proposed.

You have almost doubled the reaction chamber height. I am not sure if would outperform the BK units.

The counter current flow is not that important for a recirc skimmer (IMHO). There have been some threads that we have tried to hash out the differences betwee CC and recirc, but it ends up being a lot of speculation and very little proof either way.

The thing to remember is that the BK units have a lot of R&D behind them. Your DIY unit will need a significant amount of tweaking. The question of performance is hard to answers (I think the bulk of this thread is evidence of that).

If I had the cash, I would buy the BK
FWIW the turboflotor skimmers also appear to do VERY well.

I DIYed my skimmer because I could NOT afford the tall turboflotor and felt that I could build something that would suffice. I also had planned on doing a CC airstone unit, but as mentioned, changed the plans due to complications with regard to airstone maintenance.