DIY Skimmer, yes another one!

[Mishap]

Well, I've finally gather enough components to start my thread here.
I need to start off by thanking Landy for his help, I can't thank him enough!


Basic specs I have planned so far are:

12" diameter body, 20" tall
Neck is 5" diameter
Total height will be around 38" tall
I have a 4" PVC union for removing the cup
I also out sourced 2 key-hole flanges to a very very helpful RC member

Rough sketchup drawing of the skimmer



All the parts I have so far, minus the uni-seals


12" Tube:


5" Tube:


The skimmer lid





Flange for removing the neck from the body:


Time permitting I'll be able to start working on it this week.

For the dual recirc pumps I'm not too sure yet. It's a toss up between 2 GEN-X 4100's or 2 Sedra 9000's. Any suggestions here would be greatly appreciated.

That's all for now,

Matt

[hemi18]

for what it's worth i have 2 9000's on my DIY and i love them. mine is 10 diameter and the reaction chamber is 30 inches....i've had no problems with them for about 8 months now....skimmer works very well...

[hemi18]

by the way..how are you planning on making your cone?

[Mishap]

I'll be making the cone by building a jig from some scrap MDF and put a square of acrylic in it, then use a heat gun to soften it while I clamp the jig down. Hyperfocal has a great description on how to do it. http://reef.eldersign.org/?p=123

[sherm71tank]

Is it fair to say this will be similar to a DAS EX2?

[Mishap]

Hmm, I'm not familiar with the DAS EX2. Do you have some info on it?

The skimmers I based my designs on are the Octopus DNW-250 and Deltec AP1003.

[JCTewks]

make sure you oversize your recirc plumbing...I would use 1" for everything....1 1/4 or 1 1/2 on the skimmers output.

[hahnmeister]

Dual 9000's or 4100's? Sounds like a 2000lph skimmer, if not more. You will want a larger neck for that much... 6" for 2000lph, 7" for 2500lph, and 8" diameter for 3000lph.

[Mishap]

The intakes for the recircs are 1", output 1.5".

Thanks for the info Hahn, if I used smaller pumps could I get away with a 5" neck? The union I got for easy removal of the cup only fits 5" O.D. tubing. I'm sure I could jimmy rig it to work, or use a whole new flange altogether. Any insight you may have would be great.

Matt

[H20ENG]

Are you sure the Union is for 5"OD tubing?? I thought 4" PVC fittings only fit 4.5"OD tubing?
Can you measure it for us?

[hahnmeister]

For a 5" neck, I would go with 1000-1200lph of air.

[JCTewks]

Originally posted by hahnmeister
For a 5" neck, I would go with 1000-1200lph of air.

which could easily be done with one pump instead of two...saving yourself electricity, as well as maintenance and plumbing fittings.

[Mishap]

Oops, my mistake, it is indeed 4.5".

So I would be better off using one gen-x 4100 or 1 sedra 9000? meshmodded of course.

Matt

[JCTewks]

or one laguna 1500 (meshmodded of course )

[Mishap]

Laguna may work

[CleveYank]

Originally posted by Mishap
I'll be making the cone by building a jig from some scrap MDF and put a square of acrylic in it, then use a heat gun to soften it while I clamp the jig down. Hyperfocal has a great description on how to do it. http://reef.eldersign.org/?p=123

TY for neck stretcher link. Saw someone use heat and fire resistant bowl but this appears to have much more "predictable" result.

[kentrob11]

I used a 5" neck on mine with over 3000LPH and It worked perfectly but that said had I to do it over again I would have gone with a 6, possibly a 7" neck....

[hahnmeister]

Yeah, a narrow neck CAN and WILL work, just maybe not as well. They tend to be more 'foam cannons' and slightly harder to adjust. They tend to skim wet if in the 100+ lph/in2 range, and some have overflow problems as well because as the water rises in a narrower neck, it rises faster than in a wider neck due to the lower volume. This can be compensated for by more height, but that has its own complications.

[Mishap]

So if I made the cone taller and wider the 4.5" neck would work? Just not as well if of a wider diameter?

Thanks, Kentrobb, your skimmer was a huge inspiration in this build.

Hahn, your input really really helps!

Matt

[guido_kp]

why not use a twist lock flange for the cup to body junction? that way, youre not limited to 4.5" neck, because of the union. i see that you have access to a cnc...laser? so make your own twist flange.

why the keyhole flange on the skimmer cup lid? i understand having one from the body to cone, for cleaning the inside, but not for the cup lid.

[Mishap]

I'm beginning to rethink the union and go with another keyhole flange for the neck. Then use a 6" neck instead of the 4.5".

Also, I'm going to hook up a waste collector to the skimmer so I need an air tight lid connection

[hahnmeister]

Will this skimmer be internal or external. If internal, you could use a simpler 'water dam' system like the KZ skimmers.

[Mishap]

Internal most likely, but I would like the option of going external.

[hahnmeister]

The 'water dam' option is still possible. It CAN be used externally. I think the idea just makes some people uneasy, but really, it shouldnt ever cause any problems.



Okay, there are three arrows in the middle... the top one crosses the line where the body seperates from the cup. The funnel on the bottom of the cup is part of the cup, and then the ring around the outside (it holds the air intake hose on the left) is part of the body, as well as the ring around that. So what happens is that the foam fills this space up with some water, which acts as an airlock. If the water builds up too much, it drains back into the skimmer, but if it is too low, it will seep into this channel and prevent air and foam from escaping. The only hitch is that you must put this high up on the neck, right below the cup. If you put it down below where the waterline in the skimmer might rise above this level, then it will overflow.

The cool thing is, when you want to change the cup, you just lift it off... thats it. The tunze master DOC and Aqua Euro Classic skimmers use a similar system really. It looks alot different but it does function the same. No crappy twist-lok flanges to futz with, no keyhole flanges to waste time, and no unions that you need to torque to get off.

[hahnmeister]

I hope that makes sense. I think in the final design, that little funnel is just an inside cylinder (the neck in the cup just extends down). Easier to make and use than a twist-lock flange, thats for sure.