The Expanded Air Process (EAP) Skimmer FAQ.Copyright 1998, William Kirkpatrick, All Rights Reserved.Permission is granted for this document to be copied (unmodified) in either electronic or hardcopy form by any organization, if it is copied in its entirety and made available without fees of any kind.This document may not otherwise be published, posted, uploaded, replicated or copied by any method, electronic or physical, without explicit permission.The author is not liable in any form or fashion, nor are his employers, for how you use this information.
- Revision history:
- Revision 1.0, July 1998.
Questions and comments about this FAQ may be directed to "wkirk@snip.net". Please limit these to the design, construction, and operation of the EAP, or the improvement of this FAQ.
- Contents:
- What is an "Expanded Air Process" Skimmer?
Where do I get such a skimmer?
How big of a pump do I need?
Where do I get this Beckett Foam Jet?
How does the Beckett work?
Is a DIY version of an HSA type skimmer possible?
Are we building a clone of MTC's HSA products?
I've heard about a DIY "Super-HSA", what is that?
So, What is this skimmer officially called?
Where do I get the other parts?
How big is the EAP-2?
How big a tank does it support?
Will the EAP pull more gunk from my tank than my current skimmer?
Has anybody else built an EAP, what did they think?
Do I have to use clear PVC, its so expensive?
Can I use Acrylic?
Where do I get the plans?
Some of this is different from what I read in the Newsgroup, why? - The plans:
- What
are the major components of the EAP-2?
You just gotta have a picture, don't you?
What is the "Beckett containment chamber"?
How do I build the "Beckett containment chamber"?
How do I add air control to containment chamber?
How do I plumb my pump into containment chamber?
What is the downtube?
How do I build the downtube?
What is the sump?
How do I build the sump?
Is there special plumbing inside the sump?
How do I connect the downtube to the sump?
How do I build the riser?
How do I set the Air flow?
How do I cut the riser to proper height?
The dry foam keeps "rolling into" the wet foam, what's wrong?
How do I build the drain?
How do I build the gunk collection system?
Why doesn't the EAP have a collection cup?
I went on vacation and my gunk bottle overflowed! What can I do?
How do I get this thing to stand up?
Shouldn't the downtube be supported?
What is a "C" support?
How do I build an air filter?
Ok, really, what should NOT be glued together?
What is an "Expanded Air Process" Skimmer?
- This type of skimmer was first marketed by Marine Technical Concepts, Inc. through a product line they call the HSA (High Speed Aireation) series. The key feature of these skimmers is their use of a commonly available fountain head used for lawn and garden ponds. The fountain head is manufactured by Beckett, who calls it a "Foam jet fountain head". The Expanded Air Process skimmer is a skimmer built around the Beckett head.
- MTC sells a professional acrylic device which is held
in high regard by a number of newsgroup posters. MTC shows a good set
of pictures, one with the unit in operation, on their web page
http://www.marinetechnical.com/ . It is rumored that other manufacturers are working on models of their own.Or, you can build one.
- The original version of the skimmer used a Quiet One, which is rated at 1100 GPH at zero head. Some have reported using pumps with higher ratings. One pump reported to be working was rated 1500 GPH at 6'. Devices using lower rated pumps haven't been reported.
-
Chris Paris of CMU posted this image of the Beckett head. It can be found where lawn and garden ponds are sold. There are mail order sources that can be found on the net. Retail price at Home Depot was $15.
-
It is a venturi valve. Water is pumped in (image left), it sucks air in from the side (image center), and an air/water mix is ejected (image right). Below is another image from Chris's site that shows the inner details of the Beckett. Unlike valves found on traditional venturi skimmers, the Beckett pulls a great deal of air into the air/water mix.
- Many have claimed that "it can't be done". However, if one took all the various pieces used to build a commercial version and put them together properly, one must assume it would work. So, at least we know it can be done. The skimmer described below should be easy enough to build for anyone with basic PVC pipe fitting skills. With a little care, even a novice should be able to succeed.
- No. This skimmer does not look like MTC's HSA. It better resembles the ETS "downdraft" style of skimmer, but the resemblance is only "skin deep". The internal designs of this and the ETS are quite different.
- This is the same skimmer. The term "Super-HSA" was used over the course of the newsgroup discussion to highlight the "Super" low cost, and contact time of this skimmer over other HSA type skimmers. Even thought MTC's web site doesn't indicate they have registered "HSA" as a trade mark, I feel this version of the skimmer can stand on its own as the "EAP".
- The "EAP-2". "EAP-1" is reserved for the possibility of a smaller version.I've seen a 4" foaming head spouting a jet about 6' high at a local shopping mall. Perhaps we should reserve "EAP-3" for the first to build a workable skimmer around that puppy, any takers?
- The PVC parts were bought at Home Depot, but most any builder's store should have the fittings, tube, and Beckett head. A fair sized pump is needed, and there may be better sources than Home Depot for these. The original version used mail ordered 2" and 4" clear PVC tubing.
- It stands 4', floor to calling. It has a footprint of 5"x17". The height can be easily reduced to 3'. To get under 3' will probably require more extensive design changes.
- It supports tanks up to the size of the pump's ability to turn over 1 tank/hour. Pump size is limited by the skimmer's ability to handle the flow. If the flow is 900GPH, then it will support a 900G tank, etc. I base this estimate only on information found in the "Reefkeepers FAQ". This skimmer might do better than this, and I doubt it can do any worse.Flows rates between 900 GPH and 1500 GPH have been reported to work. The original version handles about 900 GPH (Quiet One @ 4' head).
- Who knows. In the author's opinion, probably.
Every tank is different, the same tank varies over time, each tank produces
different sets of proteins, and every installation is different. I suspect
there are just too many variables for a controlled experiment to produce
meaningful results that cover every application. Sorry about that. A
tank only produces so much gunk per day. A 100% efficient skimmer will
pull it all out on the first pass through. Nothing is 100%.If a good
skimmer is compared to a lesser one, both might still pull about the
same amount of gunk per day over the long term. They are merely matching
the tank's output. Here are some of the differences between a better
and lesser skimmer...
- The better skimmer produces more gunk in the
first few days, then settles back to the same rate of production.
If so, then the better skimmer is probably keeping the organic count
lower than the lesser one. The spike was the better skimmer lowering
the count. The tank should produce fewer nitrates over time.
- The better skimmer produces less, but more concentrated gunk. This may be hard to detect by eye, since many proteins are clear (like egg whites). Some believe skimmers that produce more concentrated gunk pull fewer trace elements from the water, but again, who knows.
- The better skimmer may shine in peak situations, like death of a specimen. It may be able to purge the water more quickly.
- The better skimmer produces less, but more concentrated gunk. This may be hard to detect by eye, since many proteins are clear (like egg whites). Some believe skimmers that produce more concentrated gunk pull fewer trace elements from the water, but again, who knows.
- The better skimmer produces more gunk in the
first few days, then settles back to the same rate of production.
If so, then the better skimmer is probably keeping the organic count
lower than the lesser one. The spike was the better skimmer lowering
the count. The tank should produce fewer nitrates over time.
- Shawn Ramsey appears to be the first to pick the EAP off the Newsgroup and build one. The first response started with "Wow.", and went on to say "I am very happy." Later postings continued to suggest the device was working well. Shawn reports to be using a 1500 GPH pump.Shawn's observations about operation of the EAP appear to confirm those made of the original version.NOTE: To insure verification work had actually been done, some information was not posted to the Newsgroup. One such detail was the quality of the foam output. The original version often ejects a thick foam that can take hours to break down. Shawn has reported the EAP was ejecting foam "like shaving cream".
- It is highly recommended. It helps show what is going on inside. It helps suggest when it needs cleaning. It's fun to show your friends... Well, maybe not. Don't be too cheap, this is a state-of-the-art device. Do it right the first time, and it won't have to do it again. The clear PVC will add to the cost, but that is nothing compared to a commercial version.The pump will run $100, so why not budget the same for the skimmer itself?
- There is such a thing as extruded acrylic tubing that is size compatible with Schedule 40 PVC fittings. It runs about 50% of the cost of PVC. It is more clear, but it is only 1/8" thick. It has been reported that extruded acrylic is more likely to crack when glued than the cell cast form. However, cell cast is more expensive than extruded.It would seem that acrylic can be cheaper and allow for greater visibility, at a cost of strength and higher potential for algae growth inside. PVC is more costly, stronger, and adds a small degree of cloudiness to the tube walls.Feel free to substitute acrylic for PVC throughout the design. In the worst case, shorten the downtube slightly to make up for the larger inside diameter of the 1/8" tube walls. 30" should be fine.
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Right here. This is the most FAQ of them all. The next document is dedicated to building an EAP-2 skimmer. click here
